D-F-Unit Guides.qxd 16-Jun-04 3:08 PM Page 7 E Reactions ... 3/Unit E.pdfhave identified that there are chemical reactions between acids and metals and between acids and carbonates

Sheet 1 of 1© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

E Unit guideReactions of metals and metalcompounds

Where this unit fits in Prior learningThis unit builds on:8E Atoms and elements and 8F Compounds and mixtures. In 7E Acids and alkalis, pupilswill have observed neutralisation reactions, and in 7F Simple chemical reactions, they willhave identified that there are chemical reactions between acids and metals and betweenacids and carbonates. However, they are unlikely to have considered the other products ofthese reactions.

The concepts in this unit are: metals and non-metals, reactions of acids with metals, metal oxides and metalcarbonates, symbols and formulae, word equations.

This unit leads onto: unit 9F Patterns of reactivity.

To make good progress, pupils starting this unit need to:• name some metals, understand that they are elements,

and give some of their characteristics• know that atoms join together in different ways when

chemical reactions take place• have represented some elements and compounds by

symbols and formulae• understand that chemical reactions can be represented

by word, particle and symbol equations and havecarried out tests to identify hydrogen and carbondioxide.

Framework yearly teaching objectives – Particles• Identify evidence which indicates that a chemical reaction has taken place, such as the association of energy transfer with chemical change.• Recognise that chemical reactions can be modelled by assuming that atoms can rearrange themselves, and that this can happen in only a limited

number of ways, for example: A + B → AB, AB + CD → AD + CB.• Use the particle rearrangement model to: predict the names and formulae for products that might be formed from given reactants; write word and

symbol equations for some simple reactions; explain how acids react with bases and neutralisation occurs.• Describe how metals react with oxygen, water, acids and oxides and solutions of salts of other metals.

Expectations from the QCA Scheme of Work At the end of this unit …

… most pupils will … … some pupils will not have made somuch progress and will …

… some pupils will haveprogressed further and will …

in terms of scientific enquiry NC Programme of Study Sc1 2b, c, d, e, f, g, i, j, k, l, m, o, p

• make observations and use these to identify similarities inchemical reactions

• use preliminary work to decide on a method for preparing a saltand suggest ways in which their method could be improved.

• make observations of chemical reactions,and show that there are patterns in these

• identify where they found difficulties inpreparing a salt.

• explain the steps they took toprepare a high-quality sample ofa salt.

in terms of materials and their properties NC Programme of Study Sc3 1a, d, f, 2h, 3a, e; Sc4 5a

• describe how metals react with acids and how acids react withmetal carbonates, metal oxides and alkalis

• identify evidence which indicates that a chemical reaction hastaken place

• represent reactions by word equations, identify patterns in theseand produce general equations

• name a variety of salts and describe the uses of some of them.

• identify that hydrogen is produced whenmany metals react with acids, and carbondioxide when acids react with carbonates,and describe tests for hydrogen andcarbon dioxide

• state that the production of a new materialis evidence of a chemical reaction.

• represent chemical compoundsby formulae and combine theseinto symbol equations

• use knowledge of reactions tomake predictions about otherreactions

Suggested lesson allocation (see individual lesson planning guides)Direct route

E1What is a metal?

E2Salt on the roads

E3Acids attackmetals

E4Acids attackcarbonates

E5Acids and metaloxides

Booster 3Focus on particles 1 –Physical changes

Extra lessons (not in Pupil book)

E5 Investigate:Making salts

Review and assess progress(distributed appropriately)

MisconceptionsPupils often confuse metallic elements with other metallic materials and similarly non-metallic elements with non-metallic materials.‘Nitrate and sulphate are elements.’ It is useful to describe nitrate and carbonate as groups that often stay together in chemical reactions.Pupils may be confused by the word salt and teachers might like to take potassium chloride as an example of a salt that is not common salt.

Additional informationWith some pupils, teachers may wish to concentrate on some new topics, but with others spend time recapping previous work.

Health and safety (see activity notes to inform risk assessment)Hazcards should be consulted and risk assessments made for all materials used. In this unit, pupils:• explore the properties of metallic and non-metallic elements • use solutions of acids, alkalis and metal salts, which may be hazardous • evaporate

salt solutions prepared in a variety of ways • plan and carry out an investigation into the preparation of a salt.

D-F-Unit Guides.qxd 16-Jun-04 3:08 PM Page 7


E1Lesson planning

guideWhat is a metal?

Suggested alternative starter activities (5–10 minutes)

Introduce the unit

Unit map for Reactions ofmetals and metalcompounds.

Learning objectivesi The uses of metals.ii Metals are shiny, good conductors of electricity and heat energy; some metals are magnetic and most metals are solids at room temperature.

Scientific enquiryiii Use tables and graphs to present melting point data for metals. (Framework YTO Sc1 9e)iv Analyse melting point data for metals, possibly using ICT. (Framework YTO Sc1 8d)

Learning outcomes

Share learning objectives

• Describe some uses of metals.• Describe how metals behave.• Use graphs and charts to

present data. (Sc1)

Problem solving

‘Why doesn’t it work?’Cartoons for classdiscussion.

Brainstorming

Metal names and uses.

Capture interest

Show pupils photos oflarge-scale metal uses.Catalyst InteractivePresentations 3

Suggested alternative plenary activities (5–10 minutes)

Review learning

Pupils work in groups to listmetal properties.

Sharing responses

Pupils feed back to wholegroup the outcomes of ActivityE1b, and discuss reasons forusing graphs to process data.

Group feedback

Sentence completion bywhole group on board.

Word game

Matching exercise tocover main points ofthe lesson.

Looking ahead

Pupils discuss how to identify gold,copper and iron and speculate ontheir reactivity. Catalyst Interactive Presentations 3

Suggested alternative main activitiesActivity

Textbook E1

Activity E1a Practical

Activity E1b Paper

Learningobjectivessee above

i and ii

ii and iii

ii, iii and iv

Description

Teacher-led explanation and questioning OR Pupils work individually,in pairs or in small groups through the in-text questions and thenonto the end-of-spread questions if time allows.

Thermal conductivity A short activity to compare the thermalconductivity of different metals.

Data about metals Pupils draw graphs of data about metals. Theywork in groups to justify the uses of metals by discussion about thedata.

Approx. timing

20 min

20 min

20 min

Target group

C H E S

R/G G R S

✔

✔

Key wordsconduct electricity, conduct thermal energy, red only: cast iron, alloy

Out-of-lesson learningHomework E1Textbook E1 end-of-spread questionsActivity E1bMake fact files about metallic elements to report back to theclass/construct a databaseFind out about how metals have been used in the past

Most pupils will ...

• describe the properties of metals and makegeneralisations about their uses

• interpret melting point data for metals.

Some pupils, making less progress will ...

• describe some of the properties of metals• interpret melting point data for metals with

help.

Some pupils, making more progresswill ...

• identify metals that are single elementsand those that are mixtures of substances

• interpret and use melting point data formetals

• explain how metals have been used in thepast, e.g. to make jewellery.



E2Lesson planning

guideSalt on the roads


Recap last lesson

Pupils identify typicalproperties of metals.

Learning objectivesi When a base neutralises an acid, a salt and water are made.ii The name of the salt comes from the names of the acid and base used to make it.iii Write word equations.

Scientific enquiryiv Make observations using pH paper (optionally dataloggers) to identify when neutralisation has taken place.

Learning outcomes


• Describe how salts are made fromacids and bases.

• Work out the names of salts.• Use pH paper to tell when

neutralisation happens. (Sc1)

Problem solving

Pupils watch a demo andthink what happens whenacids react with metals andcarbonates.

Brainstorming

Uses of common salt.

Capture interest

Safe handling of acids.


Review learning

True/false game.

Sharing responses

Groups combine to discussoutcomes of Activity E2b.

Group feedback

Groups compare salt crystalsfrom Activity E2a with othergroups and with commercialcrystals.

Word game

Anagram activity.

Looking ahead

Pupils suggest what elseacids react with.


Textbook E2

Activity E2a Practical/ICT

Activity E2b Discussion


i, ii and iii

i, ii, iii andiv

ii and iii

Description


Making sodium chloride Pupils make sodium chloride crystals usinghydrochloric acid and sodium hydroxide solution. Demonstration toshow pupils that neutralisation can be followed using dataloggingequipment.

Equations for salts Pupils use cut and paste to complete equationsfor making salts. Extension: pupils write symbol equations.

Approx. timing

20 min

30 min

10 min

Target group

C H E S

R/G G R S

✔ ✔

✔ ✔ (✔)

Key wordssalt

Out-of-lesson learningHomework E2Textbook E2 end-of-spread questionsFind out the names of salts used in household products or medicines.


• describe how a salt and water are made whenacids are neutralised by bases

• represent examples of neutralisation with generaland specific word equations

• name a variety of salts.


• describe one example of making a salt byneutralisation

• represent neutralisation with a general and aspecific word equation naming the saltcorrectly.

Some pupils, making more progresswill ...

• represent chemical compounds by formulaeand combine these into symbol equations

• use knowledge of reactions to makepredictions about other reactions

• interpret a pH curve.



E3Lesson planning

guideAcids attack metals

Learning objectivesi Many metals react with acids, causing corrosion.ii Acids react with metals, producing a salt and hydrogen gas.

Scientific enquiryiii Be able to test for hydrogen.iv Discuss whether there is enough evidence to support conclusions based on experimental outcomes. (Framework YTO Sc1 9e)


Recap last lesson

True/false game.


• Describe how metals react withacids.

• Test for hydrogen.• Decide if you have enough

evidence to make conclusions from experiments. (Sc1)

Problem solving

Pupils consider why metalstake different amounts oftime to corrode. Catalyst InteractivePresentations 3

Brainstorming (1)

Pupils predictobservations whenmagnesium is added toacid.

Brainstorming (2)

Pupils suggest why metalreactions are a nuisance.


Textbook E3


Activity E3b Practical


i, ii and iii

ii, iii and iv

ii, iii and iv

Description

Teacher-led explanation and questioning OR Pupils workindividually, in pairs or in small groups through the in-textquestions and then onto the end-of-spread questions if time allows.

Metals and acids reactions Pupils carry out and compare thereactions of magnesium, zinc and copper with three different acids.They discuss what conclusions can be made based on the evidencethey gather.

Investigate: Tin cans Pupils investigate the reaction of food acidswith iron and tin. They select a range of fruits and vegetables andinvestigate whether they react with iron and tin to decide whetherthey are suitable for canning.

Approx.timing

20 min

25 min

15 min(to set up –look at itnext lesson)

Target group

C H E S

R/G G R S

✔ ✔

✔ ✔


Review learning

Quick quiz.

Sharing responses

Whole-class discussion ofsimilarities and differences inthe reactions from Activity E3a.

Group feedback

Pupils work as groupsto discuss Activity E3aQuestion 3.

Word game

Write a question game.

Looking ahead

Pupils predict the outcomesof Activity E3b.

Learning outcomes


• describe how metals react with acids• describe the test for hydrogen.


• identify that hydrogen is produced when manymetals react with acids

• describe the test for hydrogen• know whether there is enough evidence to make

a conclusion.

Some pupils, making more progress will ...

• describe how a range of metals react with acidsand the implications of this for the food canningindustry

• be able to balance chemical equations• suggest what further work needs to be carried

out to provide firm evidence for conclusions.

Key wordsred only: balanced equation

Out-of-lesson learningHomework E3Textbook E3 end-of-spread questionsLook for examples of metal corrosion in the locality



E4Lesson planning

guideAcids attack carbonates

Learning objectivesi Carbonates neutralise acids, producing a salt, water and carbon dioxide gas.ii The production of new materials and energy changes are evidence of a chemical reaction taking place.

Scientific enquiryiii Be able to use a thermometer or temperature probe to follow a temperature change in a reaction.


Recap last lesson

Pupils look atoutcomes of ActivityE3b from previouslesson.


• Describe how metal carbonates reactwith acids.

• Identify when a chemical changehappens.

• Measure temperature changes and recordthem in tables and graphs. (Sc1)

Problem solving

Pupils classify salts interms of the acids usedto make them.

Brainstorming

Pupils brainstorm theirprevious learning aboutchemical changes.

Capture interest

Show a demo of fizzysherbet and acid rain onlimestone.


Textbook E4


Activity E4b Discussion


i and ii

i, ii and iii

i

Description


Making copper sulphate Pupils make copper sulphate from coppercarbonate and sulphuric acid. They evaluate their evidence toconsider ideas about chemical change and metal reactions.Demonstration to show pupils that the temperature changes in thereaction can be followed electronically.

Equations for carbonates Pupils use cut and paste to completeequations for making salts. Extension: pupils write symbol equations.

Approx.timing

20 min

30 min

20 min

Target group

C H E S

R/G G R S

✔

✔ ✔ (✔)


Review learning

Group team quiz.

Sharing responses

Whole-class discussion tofeed back outcomes ofActivity E4a.

Group feedback

Groups compareresponses to ActivityE4b.

Word game

Pupils work in pairsto complete Clozesentences.

Looking ahead

Pupils think about what salts would be madewhen minerals are ‘leached’ using acids.Catalyst Interactive Presentations 3

Learning outcomes


• describe how metal carbonates react withacids

• identify evidence which indicates that achemical reaction has taken place

• represent reactions with metal carbonatesby word equations, identify patterns inthese and produce general equations

• name the salts produced and describe theuses of some of them

• describe the test for carbon dioxide.


• identify that carbon dioxide is produced whenacids react with carbonates

• describe the test for carbon dioxide• state that the production of a gas is evidence

of a chemical reaction.


• represent the reaction between calcium carbonateand hydrochloric acid by a balanced chemicalequation

• given a short passage in a foreign language,explain the universality of chemical symbols andformulae

• describe a range of applications of the reactionbetween carbonates and acids.

Key wordsNone

Out-of-lesson learningHomework E4Textbook E4 end-of-spread questionsSurvey which indigestion tablets contain calcium carbonate



E5Lesson planning

guideAcids and metal oxides

Learning objectivesi Acids react with many metal oxides, producing a salt and water.ii Know the uses of some important salts.

Scientific enquiryiii Identify evidence for a reaction taking place.


Recap last lesson

Quick test.


• Describe how metal oxidesreact with acids.

• Identify evidence of areaction taking place. (Sc1)

Problem solving

Pupils examine labels and‘hunt the salt’.

Brainstorming

Concept cartoon tostimulate brainstorminguses of salts.

Capture interest

Demo of reactions of rustyiron and corroded coinswith acid.


Textbook E5


Activity E5b Paper


i and iii

i, ii and iii

ii

Description


Oxides and acids Pupils investigate what happens when metal oxidesreact with acids. They look for evidence that a reaction hashappened.

Uses of salts Pupils learn the uses of some salts by a matchingexercise involving the name, use and formula of several salts.

Approx.timing

20 min

25 min

15 min

Target group

C H E S

R/G G R S

✔ ✔ (✔)

✔ (✔)


Review learning

How many different wayscan you make a salt?

Sharing responses

Group spokesperson feedsback outcomes of ActivityE5a.

Group feedback

Groups combine to discussActivity E5b.

Word game

Writing crossword clues.

Looking back

Pupils revise andconsolidate knowledge fromthe unit.

Learning outcomes


• describe how metal oxides react with acids• identify evidence which indicates that a

chemical reaction has taken place• represent reactions by word equations,

identify patterns in these and producegeneral equations

• name a variety of salts and describe theuses of some of them.


• state that a colour change is evidence of achemical reaction.


• represent the reaction between copper oxide andsulphuric acid by a balanced chemical equation

• explain how chemical bonds form and how someatoms form groups and make bonds as a group

• name a variety of salts and describe their uses.

Key wordsNone

Out-of-lesson learningHomework E5Textbook E5 end-of-spread questionsActivity E5b



E5Lesson planning

guideInvestigate: Making salts

Learning objectivesi Investigate ways of making a salt.

Scientific enquiryii Use preliminary work to find out if a possible approach is practicable. (Framework YTO Sc1 9c)iii Evaluate methods in terms of how the yield and purity could be improved.


Setting the context

Group/class discussionabout the uses of salts.

Introduce the apparatus

Check key techniques:• reacting• filtering• evaporating.

Safety

Group work to produce safeworking guidelines.

Brainstorming

Pupils consider the differentmethods of making thesame salt.

Problem solving

Pupils criticise a method formaking a salt.

InvestigationActivity

Activity E5c Practical


i, ii and iii

Description

Making salts Pupils plan a method for making a salt. They carry outtheir experiment and record the yield.

Approx.timing

50 min

Target group

C H E S

✔ ✔ ✔


Review learning

Teacher-led review about the typeof salt produced.

Group feedback

Groups describe theirinvestigation to the class.

Analysing

Teacher-led discussion onimproving yield and purity.

Evaluating

Teacher-led brainstorm to think about scalingup salt making to an industrial scale.

Learning outcomes


• use preliminary work to decide on amethod for preparing a salt and suggestways in which their method could beimproved.


• identify where they found difficulties inpreparing a salt.


• explain the steps they took to prepare a high-quality sample of a salt.


E Unit mapReactions of metals and metal compounds


Copy the unit map and use these words to help you complete it.You may add words of your own too.

basecarbon dioxidechemical changeschemical reactionconduct electricityconduct thermal

energychloride saltelementsfizzinghigh melting point

hydrochloric acidhydrogenlighted splintlimewatermagneticneutralisationneutralisesaltsshiny solidsstrongwater

Metals and metalcompounds

Metals Metal compounds

Acids and metaloxides

Acids and metalcarbonates

Acids andmetals

Unitmaps.qxd 18-Jun-04 11:36 AM Page 5


E1 StartersWhat is a metal?

Introduce the unit� Either draw the outline of the unit map on the board

then ask pupils to give you words to add, saying where toadd them. Suggest some words yourself when necessaryto keep pupils on the right track.

� Or give out the unit map and ask pupils to work ingroups deciding how to add the listed words to thediagram. Then go through it on the board as each groupgives suggestions.

Share learning objectives� Ask pupils to write a list of FAQs they would put on a

website telling people about what a metal is. Collectsuggestions as a whole-class activity, steering pupilstowards those related to the objectives. Conclude byhighlighting the questions you want them to be able toanswer at the end of the lesson.

Problem solving� Pupils discuss the cartoons on the Pupil sheet (this can be

copied onto an OHT for full class discussion).

� Discussion in groups or as a class can focus on howmetals behave differently to other materials (anintroduction to thinking about properties).

Brainstorming� Pupils work in pairs to list the names and uses of as many

metals as possible (a short time-limit can be given).

� Combine pairs into larger groups or have a whole-classfeedback to compile a larger list.

� A variation on this activity which works well for lessable pupils is to ask them to list some uses of metals first,and then to try to name the metals that are involved ineach use.

Capture interest� Show pupils photographs of large scale uses of metals.

� Discuss the importance of metals to our lives. Ask pupils‘How will you be using metals today?’

➔ Unit map

➔ Pupil sheet

Questions1 Why doesn’t it work?

2 Why are metals used instead?

➔ Catalyst Interactive Presentations 3


Introduce the unit

Unit map for Reactions ofmetals and metalcompounds.

Share learningobjectives

• Describe some uses ofmetals.

• Describe how metals behave.

• Use graphs and charts topresent data. (Sc1)

Problem solving

‘Why doesn’t it work?’cartoons for classdiscussion.

Brainstorming

Metal names and uses.

Capture interest

Show pupils photos oflarge-scale metal uses.Catalyst InteractivePresentations 3

E-Starters.qxd 01-Apr-04 10:59 AM Page 1

E1 StartersWhat is a metal?

Problem solving

For each picture, answer the following questions

1 Why doesn’t it work?2 Why are metals used instead?


a glass hammer a plastic pan electrical cable made of string

a wooden car engine

Problem solving

For each picture, answer the following questions

1 Why doesn’t it work?2 Why are metals used instead?

a glass hammer a plastic pan electrical cable made of string

a wooden car engine

Sheet 1 of 1

StartersE1 What is a metal?

© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.



E2 StartersSalt on the roads

Recap last lesson� Show pupils the list of properties of materials from the Pupil sheet as

an OHT. Ask pupils to sort out which properties belong to metals.

� Ask pupils to give a use of a metal that depends on each property (e.g. used to make pans because of high melting point).

Share learning objectives� Write learning objectives on board and illustrate why it is important

that we know about these ideas. Tell pupils that metal salts have manyuses e.g. they are made in huge quantities for the cosmetics andpharmaceutical industries.

� Tell pupils examples e.g. magnesium and calcium carbonate inindigestion remedies, many metal salts are in make-up, shampoos andshower gels (you can show labels if there is time, possibly via a digitalmicroscope and light projector).

� Tell pupils that salts are made from acids, and ask them why it isimportant that we can check that the pH is neutral before salts are used.

Problem solving� Demonstrate the reaction of magnesium metal and calcium carbonate

powder with dilute hydrochloric acid.

� Ask pupils ‘Why does the bubbling stop?’ Focus discussion on whatmight be used up and what evidence there is from the appearance ofthe test tubes (no magnesium left, plenty of calcium carbonate left).

� Ask them to predict and then show them what happens when moremagnesium and more calcium carbonate are added.

Brainstorming� Ask pupils what common salt is used for. Encourage them to think

beyond the flavouring of food e.g. dishwashers, contact lens solutions,saline drips and medicines, salting winter roads, historical uses such assalting meat and battlefield antiseptic.

� Show them some packaging labels and identify the different names e.g salt, brine, sodium chloride, saline.

Capture interestShow pupils some stock bottles of acids with ‘corrosive’ labels. Tell pupilsthat they will be working with acids in the lesson. In pairs, ask them toproduce a ‘Safe Working’ procedure to show how they will keep themselves safe.

➔ Pupil sheet

Equipmentempty bottles of thefollowing showing names ofsalts; shower gel; shampoo;bubble bath; indigestionmedicines; (Optional)Digital microscope and lightprojector

Equipmenttwo test tubes in rack; eyeprotection; 0.4 mol/dm3

hydrochloric acid; smallpieces of magnesiumribbon; powdered calciumcarbonate and spatula

Equipmentpackaging showing thewords ‘salt’, ‘brine’, ‘sodium chloride’ or ‘saline’e.g. medicines such as‘Dioralyte’; contact lenssaline; hot dogs or tuna inbrine; dishwasher salt; tablesalt

Equipmentbottles of dilutehydrochloric and sulphuricacid; clearly visible hazardwarning corrosive signs


Recap last lesson

Pupils identify typicalproperties of metals.


• Describe how salts are made fromacids and bases.

• Work out the names of salts.• Use pH paper to tell when

neutralisation happens. (Sc1)

Problem solving

Pupils watch a demo andthink what happens whenacids react with metalsand carbonates.

Brainstorming

Uses of common salt.

Capture interest

Safe handling of acids.


E2 StartersSalt on the roads

Recap last lesson

high melting point

low melting point

shiny

solid

liquid

gas

conduct electricity

good insulator

conduct heat

hard

can be shaped




E3 StartersAcids attack metals

Recap last lesson� Read out these statements and ask pupils to hold up cards

to say whether they are True or False. (Pupils can beallowed to confer and vote as a group).

Share learning objectives� Write objectives on the board. Tell pupils that it is very

important that scientists study the reaction of acids withmetals, for example, in the motor industry steel carbodies are ‘pickled’ by dipping them in acid to get a veryclean surface for painting.

Problem solving� Pupils look at images of different metals in varying stages

of corrosion.

� Ask pupils to think about what factors affect how quicklymetals corrode away.

Brainstorming (1)� Show pupils a test tube half full of dilute hydrochloric

acid. Add pH solution.

� Ask them to list as many things as possible that they willsee happen when you add pieces of magnesium to theacid. Make a list of suggestions on the board.

� Then carry out the demo to see if they are right (youcould carry out the lighted splint test for hydrogen toshow them that the gas is made).

Brainstorming (2)� Show pupils some examples of heavily corroded metals

and tell them that corrosion is one example of metalsreacting with other substances in the air.

� Ask pupils to brainstorm a list of reasons why corrosion isa nuisance e.g. safety of vehicles, bridges, engines will notwork, difficulties with surgical implants e.g. artificial hipsetc.

� Establish that how metals react is a very important areafor scientists to understand so that they can predict howmetals will behave when they are used over long periodsof time.

Statements1 Salt is only used for adding to food. (F)

2 Alkalis neutralise acids to make salts. (T)

3 Sodium chloride salt is made everytime an acid is neutralised. (F)

4 pH paper tells us whether something isacid, alkali or neutral. (T)

5 Different acids make different salts. (T)

6 To get salt out of a solution, you heat ituntil it boils dry. (F)

➔ Catalyst Interactive Presentation 3

Suggestionstype of metal (e.g. gold does not rust);conditions (e.g. wet or warm); acid rain

Equipment0.4 mol/dm3 hydrochloric acid; pieces ofmagnesium ribbon; UI solution; chart;goggles; test tube in rack; bung; splint;matches


Recap last lesson

True/false game.


• Describe how metals reactwith acids.

• Test for hydrogen.• Decide if you have enough

evidence to make conclusionsfrom experiments. (Sc1)

Problem solving

Pupils consider why metalstake different amounts oftime to corrode.Catalyst InteractivePresentations 3

Brainstorming (1)

Pupils predict observationswhen magnesium is added toacid.

Brainstorming (2)

Pupils suggest why metalreactions are a nuisance.



E4 StartersAcids attack carbonates

Recap last lesson� Pupils look at the experiments they set up last lesson

(Activity E3b).

� Pupils record, analyse and conclude by answering thequestions on Activity E3b.

Share learning objectives� Write the learning objectives on the board. Discuss the

importance of knowing about the reactions ofcarbonates and acids by using examples such as the useof carbonates in indigestion remedies, and the need toknow how building materials such as plaster, mortar andcement will stand up to weathering due to acid rain.

Problem solving� Pupils look at the list of salts from the Pupil sheet.

Ask them to arrange them into three columnsdepending on the acid used to make them.

Brainstorming� Demonstrate an indoor firework or sparkler.

� Ask pupils to brainstorm and list evidence that achemical change has happened.

Capture interestDemonstrate:

� Why sherbet fizzes on the tongue. Add water via adropper to ‘sherbet’ powder in a test tube.

� Why limestone statues erode. Drop dilute acid ontolimestone chips on a watch glass.

� Tell pupils that both involve a reaction between an acidand a metal carbonate (sherbet is a mixture of sodiumhydrogen carbonate and citric acid).

➔ Pupil sheet

Equipmentindoor firework or sparkler and matches;heatproof mat

Ideasenergy given out as light and heat; newproducts made (ashes and gases intothe air); the change cannot be reversed

Equipment2 test tubes in rack; ‘sherbet’ powder madeby mixing equal quantities of powderedcitric acid and sodium hydrogen carbonate;water and dropper; limestone (or marble)chips on a watch glass; dilute (0.4 mol/dm3)hydrochloric acid and a dropper


Recap last lesson

Pupils look at outcomes ofActivity E3b from previouslesson.

Share learningobjectives

• Describe how metalcarbonates react withacids.

• Identify when a chemicalchange happens.

• Measure temperaturechanges and record themin tables and graphs. (Sc1)

Problem solving

Pupils classify salts in termsof the acids used to makethem.

Brainstorming

Pupils brainstorm theirprevious learning aboutchemical changes.

Capture interest

Show a demo of fizzysherbet and acid rain onlimestone.


E4 StartersAcids attack carbonates

Problem solving

1 Work out which salts can be made from the acids in the table.

2 Write the correct salts in the correct columns.

3 Which salts are left over?

Salts


sodium chloridezinc chloride copper sulphate

calcium nitrate

magnesiumsulphate

magnesiumnitrate

sodium citrate

magnesiumfluoride

Hydrochloric acid Sulphuric acid Nitric acid



E5 StartersAcids and metal oxides

Recap last lesson� Give the questions to the pupils to write individual

answers. Pupils combine into groups to produce a‘group best answers’ version.

� Check group answers through feedback and discussion.

Share learning objectives� Write the learning objectives on the board. Generate

interest by telling pupils that they will be learning howto make salts that are the same as those they see used inmedicines and cosmetics.

Problem solving� Pupils look at labels from cosmetics and medicines and,

working as a group, make a list of the salts whose namesthey recognise.

� More able pupils can suggest the names of the acidsfrom which the salts have been made.

Brainstorming� Show pupils the concept cartoon from the Pupil sheet.

� Ask them what they would say in response. Pupils workin groups to come up with a list of different uses of asmany different metal salts they can think of and thenfeed into a whole class list on the board.

Capture interest� Show pupils rusty iron items and dirty copper coins.

� Ask them to predict what will happen when they aredropped into acid.

� Use forceps to drop the nail and coin into beakers ofacid.

� Look at them at intervals during the lesson as the aciddissolves the corrosion.

� Tell pupils that the acid is reacting with metalcompounds (oxides and carbonates) on the surface ofthe metal to reveal the ‘fresh’ shiny metal underneath.

➔ Pupil sheet

Answers1 neutralisation; 2 hydrogen; 3 carbondioxide; 4 magnesium chloride; 5 corrosive.

Equipmentrange of packaging showing labels of saltsthat the pupils will recognise (metalcarbonates, chlorides, sulphates andnitrates) e.g. fertilisers, shower gels,deodorants, shampoos, bubble baths,medicines, table salts

➔ Pupil sheet

Equipment2 beakers of 0.4 mol/dm3 hydrochloricacid; corroded iron items, e.g. rusty nails,dirty, dull copper coins; forceps; watchglass; goggles


Recap last lesson

Quick test.


• Describe how metal oxides reactwith acids.

• Identify evidence of a reactiontaking place. (Sc1)

Problem solving

Pupils examine labels and‘hunt the salt’.

Brainstorming

Concept cartoon tostimulate brainstorminguses of salts.

Capture interest

Demo of reactions of rustyiron and corroded coinswith acid.



Recap last lesson

Write down what these definitions describe:

1 This word means getting rid of acid.2 This gas is made when metals react with acids.3 This gas is made when carbonates react with acids.4 This salt is made when magnesium is dropped into

hydrochloric acid.5 This is the name of the hazard warning symbol for acids.


Sheet 1 of 1

StartersE5 Acids and metal oxides

Recap last lesson

Write down what these definitions describe:

1 This word means getting rid of acid.2 This gas is made when metals react with acids.3 This gas is made when carbonates react with acids.4 This salt is made when magnesium is dropped into

hydrochloric acid.5 This is the name of the hazard warning symbol for acids.




Brainstorming

What would you say in reply to your friend who says this about salt?


The only thing I use salt for is to put it on my

chips

Sheet 1 of 1

StartersE5 Acids and metal oxides


Brainstorming

What would you say in reply to your friend who says this about salt?

The only thing I use salt for is to put it on my

chips



E5 StartersInvestigate: Making salts

Setting the context� Ask pupils to work in small groups. Pupils look back at their notes

and Pupil book to find the name and use of two salts.

� Ask a member of each group to write one salt and its use on the board.

� Give an overview of the importance and usefulness of metal salts.Tell pupils that their investigation will focus on making one salt.

Introduce the apparatus� Show pupils a solid (un-named) and an acid. Ask for a volunteer to

explain how to react the solid with the acid until the acid is just usedup. Other pupils suggest how to improve the volunteer’s method.

� Show pupils the equipment used for filtering and evaporating.

� Ask for further volunteers to explain how to filter and then how tosafely evaporate solutions. Other pupils suggest improvements.

Safety� Ask pupils in pairs to list the hazards in this investigation. Different

groups can work on different aspects e.g. handling acids, handlingsalts that may be harmful, safe evaporating procedures.

� Pupils decide how to minimise the danger presented by each hazard.

� Pairs report back to a class discussion during which a final set ofsafety procedures is listed on the board for the whole investigation.

BrainstormingThis starter works well with more able pupils.

� Pupils work in groups to make a list of different ways of making: a named sulphate salt (e.g. from metals, metal carbonates or metaloxides with sulphuric acid); a named chloride salt; a named nitratesalt.

� Each group should be given a different named salt e.g. coppersulphate, and asked to make a list of different reactions that wouldproduce their salt and a quick outline of how they would go about it.

� Use plenary discussion to tell pupils that not all methods work e.g.copper does not react with sulphuric acid

Problem solving� Show pupils the salt preparation outline on the Pupil sheet as an OHT.

� Ask them to answer the questions.

Equipmentcalcium carbonate powder onwatch glass; measuring cylinderand beaker; dilute hydrochloricacid (0.4 mol/dm3); spatula andglass rod; filter funnel; paper;evaporating basin; heatingapparatus; goggles

➔ Pupil sheet

Answers1 She lost some salt on thebench. Washing the residuewashed salt into the solution (agood idea); 2 She contaminatedher salt using a dirty glass rod;3 Add solid a little at a time. Trynot to spill any solution. Makesure all equipment is clean.Washing the residue is a goodidea.


Setting the context

Group/class discussionabout the uses of salts.

Introduce the apparatus

Check key techniques:• reacting• filtering• evaporating.

Safety

Group work to produce safeworking guidelines.

Brainstorming

Pupils consider the differentmethods of making thesame salt.

Problem Solving

Pupils criticise a method formaking a salt.


E5 StartersInvestigate: Making salts

Problem solving

1 How did Eve’s method affect how much salt she made?2 How did Eve’s method affect how pure her salt was?3 How could Eve improve her method.


1 Eve added all her solid to the acid and then stirred them together using a glass rod.

2 Eve thought there was a lot of solid on the filter paper. She washed it by pouring water through it. Some of her solution splashed on the bench.

3 Eve stirred her solution as it evaporated using the glass rod.


E1aTeacher

activity notesThermal conductivity

Running the activityThis uses rods that can be bought from educational laboratory suppliers for thispurpose. The rods have a strip of heat-sensitive plastic along one side. Theplastic changes colour when heated. Pupils use hot water to heat one end of therods, and observe the colour change.

Extended activity: pupils can process the outcome of the experiments usinggraphs or worksheets. This can feed into the data analysis in Activity 1b. As ashort plenary, the results from different groups can be compared to discuss howreliability of the measurements can be increased.

Expected outcomesSome metals are better conductors than others. The best is usually copper. Themetals available will vary according to the supplier.

PitfallsMake sure the rods are never heated with a Bunsen. There should only be asmall amount (about 1 cm depth) of hot water in the bottom of the beaker.

Safety notesPupils should take care when pouring the hot water.

Answers1 D

2 a Whichever is the best conductor.b Whichever is the least good conductor.

3 Cost, looks, durability, ‘washability’, hardness (should not scratch easily),strength (should not bend under turning force produced by contents ofpan).


Type Purpose DifferentiationPractical A short activity to compare the thermal conductivity of different metals. Core

E-Teachers.qxd 01-Apr-04 11:03 AM Page 1

E1aTechnician

activity notesThermal conductivity

EquipmentFor each group: For the class:

� set of metal rods each with attached � kettle for boiling waterthermometer of temperature-sensitiveplastic

� 250 cm3 beaker� ruler� stopwatch

For your informationRunning the activityThis uses rods that can be bought from educational laboratory suppliers for thispurpose. The rods have a strip of heat-sensitive plastic along one side. Theplastic changes colour when heated. Pupils use hot water to heat one end of therods, and observe the colour change.

Expected outcomesSome metals are better conductors than others. The best is usually copper. Themetals available will vary according to the supplier.

PitfallsMake sure the rods are never heated with a Bunsen. There should only be asmall amount (about 1 cm depth) of hot water in the bottom of the beaker.

Safety notesPupils should take care when pouring the hot water.


Type Description DifferentiationPractical A short activity to compare the thermal conductivity of different metals. Core

E-Technician.qxd 01-Apr-04 11:04 AM Page 1

E1aActivity

CoreThermal conductivity

You are going to compare different metals, to see which is the best conductor of thermal energy.

Equipment

� beaker � one rod of each type� ruler � boiling water� stopwatch

1 Look at the diagram. Which rod is thehottest?

Obtaining evidence

1 Look at a rod. On the surface is aspecial thermometer made of plastic.When the temperature of the rodincreases, the plastic will change colour.

2 Make sure you know which rod iswhich.

3 Boil some water using a kettle.4 Pour a small amount of water into your

beaker. It should only be about 1 cmdeep.

5 Put in your rods and start thestopwatch.

6 After 2 minutes, rank the metals inorder, putting the best conductor at the top.

7 Record your results.

Considering the evidence

2 Which of the metals would you use for: a the bottom of a saucepan? Give your reasons. b the handle of a saucepan? Give your reasons.

3 What else would you consider when deciding what metal touse to make saucepans?


A B C D E

metal with temperaturescale stuck on

water

The water willbe hot, so pourcarefully.

Do not handle switchesor sockets with wethands.

E-Activities.qxd 01-Apr-04 11:01 AM Page 1

E1bTeacher

activity notesData about metals

Running the activityThis activity demands that pupils think about what type of graph will besuitable for presenting the data. This can be decided via class discussion. Pupilsneed to understand that the discrete nature of the data means that continuousgraphs are not suitable. It is not intended that all pupils draw all graphs – theyshould work as a group to produce a ‘group set’ to accompany the discussionactivity.

Most pupils will be able to design their own graph axes and scales. Less ablepupils may need support in choosing an appropriate scale for their graph.

Pupils work in groups on the uses of metals. Each group can be asked to workon a different numbered box. Boxes 1 and 2 are more suitable for more ablepupils, boxes 3 and 4 are much simpler, suitable for Core and less able pupils.

ICT opportunitiesFor more able pupils, it would be possible to set up a spreadsheet for the dataand subsequent graphs.

Pupils can find more information about metals and their uses at these websites:WebElements Periodic tableRSC’s chemical science network: visual interpretation of the Table of ElementssectionBritish Royal Mint: coin specification section

Answers1 Silver has the highest electrical conductivity but would be too expensive to

use on a large scale. Copper is used most widely because it has the secondhighest electrical conductivity but is more widely available and cheaperthan silver. Aluminium is used for overhead cables because it is less densethan copper, even though it is not such a good conductor.

2 Sodium has a low melting point and so can be used as a liquid attemperatures of over 100 oC, unlike most other metals. Its thermal capacityis low compared to other metals, but these could not be used as coolantsbecause they would not melt until much higher temperatures. It can bepumped easily because it is not very dense.

3 Tungsten has a very high melting point so will not melt when it gets hot.Pupils may also link its high density to the likelihood that it will be veryhard.

4 Copper is a very good conductor of heat so that the heat is passed to thewater easily.


Type Purpose DifferentiationPaper Pupils draw graphs of data about metals. They work in groups to justify the uses of

metals by discussion about the data.Core


http://www.heinemann.co.uk/hotlinks/url.asp?urlid=9586



E1bActivity

CoreData about metals

Metals have a very wide range of uses. In this activity you aregoing to look at some data about properties of differentmetals. You will use this information to explain why eachmetal is used for a particular job.

1 Work as a group to draw suitable graphs to show thisinformation.

2 Look at the information given below. In your group, useinformation from the table and your graphs to explain whyeach metal is the best choice for these uses.


Metal Melting point Electrical Thermal (heat) Density (oC) conductivity conductivity (g/cm3)

(x 108S/m) (W/cm/K)

copper 1100 0.6 3.9 8.9

aluminium 660 0.4 2.4 2.7

tungsten 3400 0.2 1.9 19.4

silver 960 0.7 4.2 11.0

sodium 98 0.2 1.4 1.0

1 Most electrical cables are made from copper.Aluminium is used to make overhead electricitycables between pylons. Silver is not used forelectrical cables.

2 Sodium is used to cool nuclear reactors. Thecooling system is designed to melt the metaland pump it around the reactor. Sodiumabsorbs the heat and conducts it away.

3 Tungsten is used in high-speed drill bits.Friction makes the bits very hot when theyare drilling.

4 Heating elements and hot water tanks areusually made from copper.


E2aTeacher

activity notesMaking sodium chloride

Running the activityCore: The activity should be carried out in groups of two or three. Show pupils how tocarry out the method, giving particular attention to the technique of using a glass rod to test for acidity using litmus paper.

Pupils compare their crystals to crystals of commercial common salt. They will noticethat the crystals vary in size – this is due to the rate at which they form (fast-formingcrystals are smaller).

If the pupils are going to compare crystals as a group feedback Plenary, they need to leavetheir evaporating dishes on the front bench when they have finished their preparation.

Extension: The activity should be carried out in groups of two or three or as a teacherdemonstration. The experiment may be carried out using burettes instead of droppingpipettes.

An optional demonstration can be carried out to show how the pH changes duringneutralisation by using a burette to add sodium hydroxide 1cm3 at a time and followingthe pH change using a probe attached to a data logger. More able pupils should noticethat the graph of pH against volume added shows a steep step at the end point. It isalmost impossible to make an exactly neutral solution. Pupils can attempt to make anexactly neutral solution on a test-tube scale using universal indicator to show the pH.

Extended activity: More able pupils can consider how to adapt their crystallisation methodto produce different sizes of crystals.

Expected outcomesPupils will obtain sodium chloride crystals by neutralisation.

PitfallsThe drop testing can be messy unless pupils use very small drops. Encourage them towork tidily and keep their tiles clean.

Safety notesEye protection should be worn. Pupils should be warned about the risks of handling acidsand alkalis and procedures for dealing with spills and splashes on the skin.

ICT opportunitiesGo to the following website and search for ‘acids and bases’: Rader’s Chem4kids.

AnswersCore:

1 hydrochloric acid + sodium hydroxide → sodium chloride + water

2 a more sodium hydroxide would be needed b more salt made.

Extension:

3 pH probes give reading in decimal places/more accurate. Readings can be recordedautomatically, so less need for people to follow the process manually (this saves costsof wages in industry). Less intrusive to use a probe which creates less contaminationof the product.


Type Purpose DifferentiationPractical Pupils make sodium chloride crystals using hydrochloric acid and sodium hydroxide solution.

Demonstration to show pupils that neutralisation can be followed using data loggingequipment.

Core, Extension


ICT


E2aTechnician

activity notesMaking sodium chloride

EquipmentFor each group:

� 10 cm3 measuring cylinder, small beaker, glass rod, dropping pipette, white tile, evaporating dish, beaker of suitable size for water bath, bunsen, mat, tripod, gauze

� 0.4 mol/dm3 solutions of both hydrochloric acid and sodium hydroxide� concentration of solutions: it is important that 10cm3 acid needs more than 9cm3

sodium hydroxide for neutralisation. [As close to 10 cm3 as possible, so it is ideal to test it out before the lesson.]

� litmus paper� (optional) Universal indicator and test tubes� access to commercial salt crystals, e.g. table salt, rock salt, ‘sea salt’ larger crystals

Additional equipment for extension

� solutions as above� pH sensor or probe attached to datalogger with screen or hand-held pH sensor

For your informationRunning the activityCore: The activity should be carried out in groups of two or three. Show pupils how to carry out the method, giving particular attention to the technique of using a glass rod to test for acidity using litmus paper.

Pupils compare their crystals to crystals of commercial common salt. They will notice that the crystals vary in size – this is due to the rate at which they form (fast-forming crystals are smaller).

If the students are going to compare crystals as a group feedback Plenary, they need to leave their evaporating dishes on the front bench when they have finished their preparation.

Extension: The activity should be carried out in groups of two or three pupils or as a teacher demonstration. The experiment may be carried out using burettes instead of dropping pipettes, if preferred.

An optional demonstration can be carried out to show how the pH changes during neutralisation by using a burette to add sodium hydroxide 1cm3 at a time and following the pH change using a probe attached to a data logger. More able pupils should notice that the graph of pH against volume added shows a steep step at the end point. It is almost impossible to make an exactly neutral solution.Pupils can attempt to make an exactly neutral solution on a test-tube scale using universal indicator toshow the pH.

Extended activity: More able pupils can consider how to adapt their crystallisation method to producedifferent sizes of crystals.

Expected outcomesPupils will obtain sodium chloride crystals by neutralisation.

PitfallsThe drop testing can be messy unless pupils use very small drops. Encourage them to work tidily and keep their tiles clean.

Safety notesEye protection should be worn.

Pupils should be warned about the risks of handling acids and alkalis and procedures for dealing with spills and splashes on the skin.


Type Purpose DifferentiationPractical Pupils make sodium chloride crystals using hydrochloric acid and sodium hydroxide solution.

Extension task uses a pH sensor to check for neutralisation.

Core, Extension


E2aActivity

CoreMaking sodium chloride

In this activity, you are going to make sodium chloride(common salt) by neutralising hydrochloric acid with sodiumhydroxide. You will use an indicator (litmus) to show when theacid has been neutralised.


drops ofsodiumhydroxide

glass rod

10 cm3

hydrochloricacid +9 cm3 sodium hydroxide

litmus paper

Litmus paper goes redin acid.

tile

evaporating dish

water

Wear eyeprotection.

Take carehandlingacid. Wash

it off if you get anyon yourself.

1 Put 10 cm3 hydrochloric acid into a beaker.2 Use a glass rod to put a small drop from your beaker

onto a piece of litmus paper. The red colour shows that the drop contains acid.

3 Add 9 cm3 sodium hydroxide to your beaker and stir it using the glass rod.

4 Test a drop using a fresh piece of litmus paper (it should still show that there is acid left).

5 Add sodium hydroxide a few drops at a time. Test a drop from the beaker each time, until the litmus does not turn red – you have nowused up all the acid (it is neutralised).

6 Pour the solution you have made into an evaporating dish. Heat the solution gentlyusing a water bath.

7 Stop heating when crystals start to appear, and leave the dish to cool.8 Use a hand lens to look at your crystals and compare them to ‘salt’ crystals sold in

shops.

1 Write a word equation for making sodium chloride.2 The hydrochloric acid and sodium hydroxide you used were of the same

concentration.a If you used very concentrated acid, how would this change the amount of sodium

hydroxide you would need?b How would this change the amount of sodium chloride you made?


E2aActivity

ExtensionMaking sodium chloride

In this activity, you are going to make sodium chloride byneutralising hydrochloric acid with sodium hydroxide. You will use a pH meter to show when the neutralisation hashappened.

1 Put 10 cm3 of hydrochloric acid into a beaker.

2 Add 9 cm3 of sodium hydroxidesolution (alkali). Stir well.

3 Use a pH meter or sensor tomeasure the pH. Add more alkalidrop by drop until the pH is 7, orclose to 7. Stir well while doing this.

4 Pour the solution into anevaporating dish.

5 Heat the solution gently over awater bath to evaporate the water.When crystals start to appear, turnoff the Bunsen burner then removethe evaporating dish and leave it tocool.

6 Use a hand lens to look at yourcrystals and compare them to ‘salt’crystals sold in shops.

1 Write a word equation for makingsodium chloride.

2 The hydrochloric acid and sodiumhydroxide you used were of thesame concentration.

a If you used very concentratedacid, how would this change theamount of sodium hydroxide you would need?

b How would this change the amount of sodium chlorideyou made?

3 Most people who measure pH as part of their job use pHprobes instead of indicator paper. What are theadvantages of using pH probes?


Wear eyeprotection.



evaporating dish

water

10 cm3

hydrochloric acid

9 cm3 sodiumhydroxide solution

pH sensor/meter


E2bTeacher

activity notesEquations for salts

Running the activityRemind pupils of the equation for neutralisation of an acid using a metalhydroxide. Encourage them to work as a group before they stick their finalequations in the book.

Although not of concern to pupils, note that the reaction between calciumhydroxide and sulphuric acid may, in practice, give a milky precipitate becausecalcium sulphate is sparingly soluble, rather than the colourless solutionusually associated with reactions between metal hydroxides and acid.

Core: Cut and paste equations from Core worksheet.

Help: Cut and paste equations from Help worksheet.

Extension: Use provided formulae to produce symbol equations.

AnswersCore/Help:

hydrochloric acid + potassium hydroxide → potassium chloride + watersulphuric acid + calcium hydroxide → calcium sulphate + waternitric acid + sodium hydroxide → sodium nitrate + water

Core/Extension:

HNO3 + NaOH → NaNO3 + H2OHCl + KOH → KCl + H2O


Type Purpose DifferentiationDiscussion Pupils use cut and paste to complete equations for making salts.

Extension: pupils write symbol equations.Core (Extension), Help


E2bActivity

CoreEquations for salts

Salts have many different uses. You are going to write wordequations to show how some useful salts can be made.

Sodium nitrate is used to make fireworks and rocket fuels explode.Potassium chloride can be used instead of sodium chloride toflavour food.Calcium sulphate is used in plaster for walls and broken arms!

1 Cut out the boxes and discuss how they can be arranged tomake equations for making the salts named above. Stick them in your book in the right order.Remember: acid + alkali (metal hydroxide) →→ salt + water

2 Use these formulae to write symbol equations for makingpotassium chloride and sodium nitrate.

Hydrochloric acid: HCl

Nitric acid: HNO3

Water: H2O

Sodium hydroxide: NaOH

Potassium hydroxide: KOH

Potassium chloride: KCl

Sodium nitrate: NaNO3


→→ ++ ++ hydrochloric calcium potassium water acid sulphate hydroxide

→→ ++ ++ water nitric acid sulphuric acid potassium chloride

→→ ++ ++ sodium water calcium sodium hydroxide hydroxide nitrate

Extension


E2bActivity

HelpEquations for salts

Salts have many different uses. You are going to write word equations to show how some useful salts can be made.

Sodium nitrate is used to make fireworks and rocket fuels explode.Potassium chloride can be used instead of sodium chloride to flavour food.Calcium sulphate is used in plaster for walls and broken arms!

1 Look at the word equations below. Some of the words are missing. The boxes contain the missing words. Cut them out and discuss where they go. When you are sure, stick them in their correct places.

Remember: acid + alkali (metal hydroxide) →→ salt + water

+ potassium hydroxide →→ potassium chloride +

sulphuric acid + →→ + water

+ →→ sodium nitrate + water


calcium hydroxide

hydrochloric acid

water

sodium hydroxide

calcium sulphate

nitric acid


E3aTeacher

activity notesMetals and acids reactions

Running the activityDemonstrate how to add magnesium safely to acid in a test-tube rack and show how tocarry out the test for hydrogen. Pupils carry out the magnesium experiments. A shortdiscussion of outcomes would be useful here (see below). Pupils then compare thereactions of zinc and copper.

Note: The pupils are asked to record a temperature change during the experiment. Ideasabout chemical change and energy change do not occur until next lesson. At this point,the temperature change needs to be treated as evidence that a change is happening in thetest tube. This idea will be further developed to consider chemical change formally in thenext lesson.

Core: A table to copy is provided for magnesium. Pupils draw their own tables for theother metals.

Help: Blank tables are available for pupils to record their observations.

Expected outcomesDiscuss the outcomes in terms of the similarities (e.g. hydrogen always made, magnesiumreacts and dissolves) and differences (different salts made, a difference in rate may beseen). Pupils may also notice that there is a temperature increase during the reaction.

Pupils discuss the conclusions given in 3 within their groups. They need to look at whatevidence supports, or does not support each conclusion. They should realise that not allmetals (e.g. copper) react with acid, but when reactions do happen they usually involve theevolution of hydrogen and a temperature increase. The salt made depends on the acid used.

More able pupils may be interested to compare the formulae for the three acids and linkthe idea that sulphuric acid usually reacts faster because it contains two hydrogen atoms(i.e. twice as much ‘acid’) per molecule.

PitfallsThe test for hydrogen is tricky. The pupils need to allow the gas to build up beforetesting. When using zinc, not enough hydrogen is given off for the test to be reliable.

Pupils may well fill in ‘Salt formed’ row in the table for copper salts. As copper does notreact, there is no salt formed! This line in the table has been omitted on the Help sheet.

Safety notesEye protection should be worn and pupils reminded of how to handle acids and what todo if they get any on their skin.

Answers1 Magnesium reacts and dissolves, hydrogen is made (lighted splint pops), temperature

increase.

2 Sulphuric acid reacts faster, different salts made.

3 1 Not all metals react with acids.Statements 2 and 3 are correct.4 The salt made depends on the acid.

4 Answers will vary.


Type Purpose DifferentiationPractical Pupils carry out and compare the reactions of magnesium, zinc and copper with three

different acids. They discuss what conclusions can be made based on the evidence theygather.

Core, Help


E3aTechnician

activity notesMetals and acids reactions


� test tubes, bungs, thermometer and rack� 0.4 mol/dm3 hydrochloric, sulphuric and nitric acid� small pieces of magnesium, zinc and copper� splints and access to a lighted Bunsen

For your informationRunning the activityDemonstrate how to safely add magnesium to acid in a test-tube rack and showhow to carry out the test for hydrogen. Pupils carry out the magnesiumexperiments. A short discussion of outcomes would be useful here (see below).Pupils then compare the reactions of zinc and copper.

Note: The pupils are asked to record a temperature change during theexperiment. Ideas about chemical change and energy change do not occur untilnext lesson. At this point, the temperature change needs to be treated asevidence that a change is happening in the test tube. This idea will be furtherdeveloped to consider chemical change formally in the next lesson.

Core: A table to copy is provided for magnesium. Pupils draw their own tablesfor the other metals.

Help: Blank tables are available for pupils to record their observations.

Expected outcomesDiscuss the outcomes in terms of the similarities (e.g. hydrogen always made,magnesium reacts and dissolves) and differences (different salts made, adifference in rate may be seen). Pupils may also notice that there is atemperature increase during the reaction.

Pupils discuss the conclusions given in 3 within their groups. They need tolook at what evidence supports, or does not support each conclusion. Theyshould realise that not all metals (e.g. copper) react with acid, but whenreactions do happen they usually involve evolution of hydrogen and atemperature increase. The salt made depends on the acid used.

More able pupils may be interested to compare the formulae for the three acidsand link the idea that sulphuric acid usually reacts faster because it containstwo hydrogen atoms (i.e. twice as much ‘acid’) per molecule.

PitfallsThe test for hydrogen is tricky. The pupils need to allow the gas to build upbefore testing. When using zinc, not enough hydrogen is given off for the testto be reliable.

Pupils may well fill in ‘Salt formed’ row in the table for copper salts. As copperdoes not react, there is no salt formed! This line in the table has been omittedon the Help sheet.

Safety notesEye protection should be worn and pupils reminded of safe acid handling.


Type Purpose DifferentiationPractical Pupils carry out and compare the reactions of magnesium, zinc and copper with three

different acids. They discuss what conclusions can be made based on the evidence theygather.

Core, Help


E3aActivity

CoreMetals and acids reactions

Most metals react with acids to make hydrogen and a salt. Inthis activity you are going to look for evidence for the similaritiesand differences when different metals react with different acids.

Obtaining evidence

1 Add hydrochloric acid to a test tube until it is a quarter full. Take the temperature of the acid.

2 Add a small piece of magnesium.3 Insert a bung in the top of the tube to allow the gas to build up,

and carry out the ‘lighted splint’ test to show that it is hydrogen.4 Take the temperature of the acid after the reaction has finished.5 Repeat the experiment, using magnesium with sulphuric acid and

then with nitric acid.

Presenting the results

6 Copy and complete the following table to show what you seeand give the names of the salts that are made.


Pop!

thermometer

thermometer

magnesiumhydrochloricacid

Wear eyeprotection.




E3aActivity

CoreMetals and acids reactions (continued)


1 What changes did you see when magnesium reacts withdifferent acids?

2 What differences are there in the reaction of magnesium withdifferent acids?

7 Carry out the experiments again to investigate the changeswhen zinc and then copper are added to separate test tubescontaining the three acids.

8 Draw a table to record your observations.

Evaluating

3 Eve carried out the experiment and wrote these conclusions inher book. Decide which conclusions fit the evidence andwhich do not.

4 Re-write Eve’s conclusions so that they fit the evidence.


magnesium magnesium magnesiumand hydrochloric and sulphuric and nitricacid acid acid

observations

temperaturechange

result ofhydrogen test

name of saltformed

1 All metals react with acids.

2 When metals react with acids, hydrogen bubbles off.

3 Metals and acids give out energy when they react.

4 Magnesium always makes the same salt when it reacts

with acids.


E3aActivity

HelpMetals and acids reactions

Use these tables to record your observations.


magnesium and magnesium and magnesium andhydrochloric acid sulphuric acid nitric acid

observations

temperaturechange


name of saltformed

zinc and zinc and zinc andhydrochloric acid sulphuric acid nitric acid

observations

temperaturechange


name of saltformed

copper and copper and copper andhydrochloric acid sulphuric acid nitric acid

observations

temperaturechange



E3bTeacher

activity notesInvestigate: Tin cans

Running the activityPupils should work in groups of two or three.

Core: The activity is in two parts. Pupils first test the effects of citric acid on ironand tin. They then test some fruits and vegetables. The method is given on theactivity sheet. The experiment will need to be left until next lesson for theresults to be seen. Pupils can then record, analyse, and conclude as a starteractivity.

Help: Pupils use the Core activity sheet for the experimental method, thenrecord their results and answer the questions on the Help sheet.

Note that the investigation could be extended to find out whether the food willhave a greater reaction if it is left in the can for longer.

Expected outcomesPupils should find that the acid foods react with the iron and in some cases alsowith the tin. This can lead to discussions about why tin cans are made of iron(steel) coated with tin.

PitfallsPre-testing is necessary since results will vary with different foods.


Remind pupils to handle the powdered metals with care as they can irritate the skin.

Hands should be washed afterwards.

Remind pupils not to eat the food samples.

ICT opportunitiesA history of the can, how cans are made, and a time line can be found on thewebsite: Can Central – information about the can industry.

AnswersCore:

1 iron

2 acid

3 Tin reacts less than iron with the acid in the food.

4 Foods which react with both metals would be unsuitable (refer to acidcontent).

Help:

1 iron, tin, reacted, acid, tin, iron, tin


Type Purpose DifferentiationPractical Pupils investigate the reaction of food acids with iron and tin. They select a range of

fruits and vegetables and investigate whether they react with iron and tin to decidewhether they are suitable for canning.

Core, Help



E3bTechnician

activity notesInvestigate: Tin cans

EquipmentFor each group:� 2 test tubes � samples of fruits and� 2 spatulas vegetables, e.g. lemons,� citric acid crystals onions, carrots, tomatoes, � iron powder rhubarb, apples� tin powder � pestle and mortar� knife � spotting tile� chopping board � glass rod

or ceramic tile � dropper pipette

For your informationRunning the activityPupils should work in groups of two or three.

Core: The activity is in two parts. Pupils first test the effects of citric acid on ironand tin. They then test some fruits and vegetables. The method is given on theactivity sheet. The experiment will need to be left until next lesson for theresults to be seen. Pupils can then record, analyse, and conclude as a starteractivity.

Help: Pupils use the Core activity sheet for the experimental method, thenrecord their results and answer the questions on the Help sheet.

Note that the investigation could be extended to find out whether the food willhave a greater reaction if it is left in the can for longer.

Expected outcomesPupils should find that the acid foods react with the iron and in some cases alsowith the tin. This can lead to discussions about why tin cans are made of iron(steel) coated with tin.

PitfallsPre-testing is necessary since results will vary with different foods.


Remind pupils to handle the powdered metals with care as they can irritate the skin.

Hands should be washed afterwards.

Remind pupils not to eat the food samples.

ICT opportunitiesA history of the can, how cans are made, and a timeline can be found on thewebsite: Can Central – information about the can industry.


Type Purpose DifferentiationPractical Pupils investigate the reaction of food acids with iron and tin. They select a range of

fruits and vegetables and investigate whether they react with iron and tin to decidewhether they are suitable for canning.

Core, Help



E3bActivity

CoreInvestigate: Tin cans

Some foods contain acids e.g. citric acid. Food cans are made of steel (mainly iron) and tin. You are going to find out how the acids in food affect iron and tin.

Part A: Obtaining evidence

1 Take two test tubes and add 2 cm3 of water to each test tube.

2 Dissolve half a spatula of citric acidcrystals in each tube.

3 Put half a spatula of iron powder intoone of the test tubes, and half aspatula of tin powder into the other test tube.

4 Write down your observations in a results table.

Part B: Obtaining evidence

5 Choose four different fruits orvegetables.

6 Mash each food to a pulp.7 Place one spatula of each food on

three wells of a spotting tile.8 Add one drop of water to each food sample.9 Mix the food in each well with a clean glass rod.10 Do not add anything to the first sample of each food.11 Add a few grains of iron powder to the second sample of each food.12 Add a few grains of tin powder to the third sample of each food.13 Leave till next lesson.14 Record your results (you will need to draw a table).


1 Which metal reacted most with the foods?2 What kind of substance do some foods contain that reacts with metals?3 Why do you think that tin cans are made of iron that has been coated

with tin?4 Do you think that any of the foods you tested are unsuitable for canning?

Explain.


ironpowder

tinpowder

citric acid

food 4food 3food 2food 1

water added

iron + water added

tin + water added

Wear eyeprotection.

Handlepowderedmetals

with care. Washhands afterwards. Donot eat food samples.


E3bActivity

HelpInvestigate: Tin cans

Use these tables to record your observations.

Part A: Presenting the results

Part B: Presenting the results


1 Complete the sentences. Choose words from this list to fill in the gaps.

acid alkali iron reacted tin

The metal that reacted the most with the food was .

The metal that reacted the least with the food was .

Iron with the in food more than with

the .

Food cans are made of steel, which contains mostly .

This has been coated with .


Test tube Observation

citric acidand iron

citric acidand tin

Observations

Water only Iron and Tin andName of food added water added water added


E4aTeacher

activity notesMaking copper sulphate

Running the activityHighlight the importance of careful handling of the substances involved. Pupils may needreminding how to carry out filtering and evaporating safely. Tell pupils to wait betweenadditions of copper carbonate to check that each spatulaful is fully reacted before addingmore. The final crystals can be compared to ‘stock’ copper sulphate crystals.

Extended activity: More able pupils can record the temperature changes after each spatula isadded – they will need to introduce timing e.g. adding small spatulas every 15s. This datacan be graphed. The end of the reaction will be identifiable by the maximum temperaturerecorded. Pupils can compare the results across groups. Ask them to evaluate reasons whythe temperature changes vary between groups.

Other relevant materialSkill sheet 5: Drawing charts and graphs

Expected outcomesPupils should see that they have made some copper sulphate crystals.

Core: Pupils need to be confident at handling the techniques of adding solid to just excessand using evaporation to feed into the investigation.

Extended activity: Pupils should be able to evaluate evidence for a chemical change. Theyshould realise that to make the experiment reliable they need to control how muchcarbonate is added each time.

PitfallsPupils may add too much copper carbonate too quickly – good technique is to just reachexcess.

Safety notesEye protection is needed. 0.4 mol/dm3 sulphuric acid is classified ‘irritant’. Copper salts areharmful. Pupils need to handle substances carefully and wash off any splashes on the skinimmediately. Evaporation should stop when crystals start forming to stop ‘spitting’. Careneeds to be taken with hot apparatus.

ICT opportunitiesA demonstration can be carried out (this can be run alongside the pupil activity), using atemperature probe and data logger. The graph can be used as part of a plenary discussion todiscuss reasons why the temperature stops increasing.

Answers1 No more fizzing when more solid is added, no further temperature change, solid no

longer reacts/dissolves.

2 copper carbonate + sulphuric acid → copper sulphate + water + carbon dioxide

3 new substance made (e.g. copper sulphate and fizzing due to carbon dioxide), energy isgiven out, reaction is not easily reversed.


Type Purpose DifferentiationPractical Pupils make copper sulphate from copper carbonate and sulphuric acid. They evaluate

their evidence to consider ideas about chemical change and metal reactions.

Demonstration to show pupils that the temperature changes in the reaction can befollowed electronically

Core


E4aTechnician

activity notesMaking copper sulphate


Demo (optional):

� Datalogger and temperature probe

Other relevant materialSkill sheet 5: Drawing charts and graphs

For your informationRunning the activityHighlight the importance of careful handling of the substances involved. Pupils may need remindinghow to carry out filtering and evaporating safely. Tell pupils to wait between additions of coppercarbonate to check that each spatulaful is fully reacted before adding more. The final crystals can becompared to ‘stock’ copper sulphate crystals.

Extended activity: More able pupils can record the temperature changes after each spatula is added –they will need to introduce a timing e.g. adding small spatulas every 15s. This data can be graphed.The end of the reaction will be identifiable by the maximum temperature recorded. Pupils cancompare the results across groups. Ask them to evaluate reasons why the temperature changes varybetween groups.

Expected outcomesPupils should see that they have made some copper sulphate crystals.

Core: Pupils need to be confident at handling the techniques of adding solid to just excess and usingevaporation to feed into the investigation.

Extended activity: Pupils should be able to evaluate evidence for a chemical change. They should realisethat to make the experiment reliable they need to control how much carbonate is added each time.

PitfallsPupils may add too much copper carbonate too quickly – good technique is to just reach excess.

Safety notesEye protection is needed. 0.4 mol/dm3 sulphuric acid is classified as an ‘irritant’. Copper salts areharmful. Pupils need to handle substances carefully and wash off any splashes on the skinimmediately. Evaporation should stop when crystals start forming to stop ‘spitting’. Care needs to betaken with hot apparatus.

ICT opportunitiesA demonstration can be carried out (this can be run alongside the pupil activity), using a temperatureprobe and data logger. The graph can be used as part of a plenary discussion to discuss reasons whythe temperature stops increasing.


Type Purpose DifferentiationPractical ICT

Pupils make copper sulphate from copper carbonate and sulphuric acid. They evaluatetheir evidence to consider ideas about chemical change and metal reactions.Demonstration to show pupils that the temperature changes in the reaction can befollowed electronically.

Core

� copper carbonate� 0.4 mol/dm3 sulphuric acid� spatula� thermometer� beaker, 100 ml measuring cylinder� filter funnel and paper, evaporating dish

� beaker of size suitable for water bath� heating apparatus: Bunsen, tripod, mat, gauze� samples of copper sulphate crystals (to look at) of

varying size if possible� Extension pupils may request a stopclock


E4aActivity

CoreMaking copper sulphate

Copper sulphate is a salt with many important uses. It is toxicand is used as a wood preserver because it kills the fungi thatrot wood.

You are going to make some copper sulphate by reactingcopper carbonate with sulphuric acid.


coppersulphatesolution

20 cm3

sulphuricacid

thermometer

copper carbonate

evaporating dish

water

Wear eyeprotection.

Coppersulphate isharmful.

Clean up any splashes immediately. Take care with hotapparatus.

Obtaining the evidence

1 Put 20 cm3 sulphuric acid into a beaker.2 Take the temperature of the acid.3 Add a spatula of copper carbonate, stir it gently using

the thermometer and look for any changes you see.Make a note of the temperature on rough paper.

4 When the reaction stops, repeat step 3. 5 Stop adding copper carbonate when no more

changes happen.6 Your beaker now contains ‘left over’ solid copper

carbonate. Filter this off, carefully collecting the copper sulphate solution you have made in anevaporating dish.

7 Heat your solution gently over a water bath. Stopheating when crystals appear and leave your dish to cool.


1 What evidence did you see to show that the reactionhad stopped?

2 Write an equation for the reaction.3 What evidence is there that this is a chemical change?


E4bTeacher

activity notesEquations for carbonates

Running the activityCore: Pupils cut out the boxes and discuss how they can be arranged. They should not stickthem down until they are sure they are correct. (Note: the equation for iron sulphate usesiron (II) compounds, not iron (III). Iron tablets contain iron (II) sulphate.)

Help: An alternative sheet is provided for help with the equations partially completed.

Extension: Pupils use provided formulae to write formulae equations for the reactions.

Other relevant materialSkill sheet 15: Word equations

Skill sheet 33: More word equations

AnswersCore/Help:

iron carbonate + sulphuric acid → iron sulphate + water + carbon dioxidecalcium carbonate + hydrochloric acid → calcium chloride + water + carbon dioxidemagnesium carbonate + sulphuric acid → magnesium sulphate + water + carbon dioxide

Extension:

FeCO3 + H2SO4 → FeSO4 + CO2+ H2OMgCO3 + H2SO4 → MgSO4 + CO2+ H2O


Type Purpose DifferentiationDiscussion Pupils use cut and paste to complete equations for making salts.

Extension: pupils write symbol equations.Core (Extension), Help


E4bActivity

CoreEquations for carbonates

You are going to write word equations to show how someuseful salts can be made using metal carbonates and acids.

Iron sulphate is used to make ‘iron tablets’ for people who areanaemic.Calcium chloride is packed into little bags with new cameras tokeep them dry during storage.Magnesium sulphate is used in medicines for upset stomachs.

1 Cut out the boxes and discuss how they can be arranged tomake equations for making the salts named above. Stick themin your book in the right order.

Remember: metal carbonate + acid →→ salt + water + carbon dioxide


→→ + + hydrochloric calcium potassium carbon acid carbonate carbonate dioxide

→→ + + water sulphuric sulphuric magnesium acid acid sulphate

→→ + + iron sulphate carbon iron carbonate calcium dioxide chloride

+ + + carbon dioxide water water

Extension

2 Use these formulae to write symbol equations for making ironsulphate and magnesium sulphate.

Water: H2O

Carbon dioxide: CO2

Magnesium carbonate: MgCO3

Magnesium sulphate: MgSO4

Iron carbonate: FeCO3

Iron sulphate: FeSO4

Sulphuric acid: H2SO4


E4bActivity

HelpEquations for carbonates

You are going to write word equations to show how some useful salts can be made using metal carbonates and acids.

Iron sulphate is used to make ‘iron tablets’ for people who are anaemic.Calcium chloride is packed into little bags with new cameras to keep them dry during storage.Magnesium sulphate is used in medicines for upset stomachs.

1 Look at the word equations below. Some of the words are missing. The boxes contain the missing words. Cut them out and discuss where they go. When you are sure, stick them in their correct places.

Remember: metal carbonate + acid →→ salt + water + carbon dioxide

+ sulphuric acid →→ iron sulphate + + carbon dioxide

calcium carbonate + →→ + water +

+ →→ magnesium sulphate + +


iron carbonate

calcium chloride

sulphuric acid

magnesium carbonate

carbon dioxide

carbon dioxide

water

waterhydrochloric

acid


E5aTeacher

activity notesOxides and acids

Running the activityAsk pupils to predict the names of the salts that will be made when the oxides and acids react together.They fill in the first column of the table.

Pupils then carry out the first reaction, between copper oxide and nitric acid. At this point you may stopthe lesson briefly to discuss the outcomes before the pupils continue to help focus on the main evidence tolook for. Key points to stress are that the oxide disappears as it reacts with the acid (use the word ‘react’rather than ‘dissolves’). The point should be made that this change is less clearly seen than when acidsreact with metals or carbonates as there is no gas made, hence no fizzing. Pupils should note that there is atemperature increase, which is further evidence of a reaction happening. They fill in the second column ofthe table.

Core: Pupils carry out the rest of the activity and look for evidence of a chemical change happening.

Help: There is an additional sheet available so that pupils do not need to copy the table. The names of thesalts are given for the pupils to select from and additional support is given with observations.

Extension: Pupils write word equations for the reactions they see and identify reasons why reactionsbetween oxides and acids are more difficult to follow.

Expected outcomesCore/Help: When oxides react with acids, the oxide disappears, there is a temperature increase and, forcopper oxide, the solution turns blue/green.

Extension: As above, plus awareness that oxide reactions are less easily followed as there is no gas made.

PitfallsPupils may think that oxides ‘dissolve’ in acids. This is not the case – they react to form products that aresoluble, and so it is the products that dissolve. This is not a key teaching point, but more able pupils shoulduse the word ‘react’ throughout. The fact that oxides are insoluble can be shown by adding an oxide to atest tube of water.

Safety notesMost 0.4 mol/dm3 acids are classified as ‘irritant’. Most metal salts are harmful. Care needs to be taken andany splashes on the skin should be washed off with water immediately. Eye protection should be worn.

AnswersCore:

1 Reactions happen in every case.

2 Metal oxides disappear. All reactions give a temperature increase. Copper oxide reacts to form ablue/green solution.

Extension:

3 Any two equations from:copper oxide + nitric acid → copper nitrate + waterzinc oxide + hydrochloric acid → zinc chloride + watercopper oxide + sulphuric acid → copper sulphate + watermagnesium oxide + hydrochloric acid → magnesium chloride + water

4 Both zinc and zinc carbonate produce gases so it is easier to see fizzing.


Type Purpose DifferentiationPractical Pupils investigate what happens when metal oxides react with acids. They look for

evidence that a reaction has happened. Core (Extension), Help


E5aTechnician

activity notesOxides and acids


� copper oxide, zinc oxide, magnesium oxide� 0.4 mol/dm3 sulphuric acid, nitric acid, hydrochloric acid� test tubes, racks, spatulas� thermometer

For your informationRunning the activityAsk pupils to predict the names of the salts that will be made when the oxidesand acids react together. They fill in the first column of the table.

Pupils then carry out the first reaction, between copper oxide and nitric acid. Atthis point you may stop the lesson briefly to discuss the outcomes before thepupils continue to help focus on the main evidence to look for. Key points tostress are that the oxide disappears as it reacts with the acid (use the word‘react’ rather than ‘dissolves’). The point should be made that this change is lessclearly seen than when acids react with metals or carbonates as there is no gasmade, hence no fizzing. Pupils should note that there is a temperature increase,which is further evidence of a reaction happening. They fill in the secondcolumn of the table.

Core: Pupils carry out the rest of the activity and look for evidence of achemical change happening.

Help: There is an additional sheet available so that pupils do not need to copythe table. The names of the salts are given for the pupils to select from andadditional support is given with observations.

Extension: Pupils write word equations for the reactions they see and identifyreasons why reactions between oxides and acids are more difficult to follow.

Expected outcomesCore/Help: When oxides react with acids, the oxide disappears, there is atemperature increase and, for copper oxide, the solution turns blue/green.

Extension: As above, plus awareness that oxide reactions are less easily followedas there is no gas made.

PitfallsPupils may think that oxides ‘dissolve’ in acids. This is not the case – they reactto form products that are soluble, and so it is the products that dissolve. This isnot a key teaching point, but more able pupils should use the word ‘react’throughout. The fact that oxides are insoluble can be shown by adding anoxide to a test tube of water.

Safety notesMost 0.4 mol/dm3 acids are classified as ‘irritant’. Most metal salts are harmful.Care needs to be taken and any splashes on the skin should be washed off withwater immediately. Eye protection should be worn.


Type Purpose DifferentiationPractical Pupils investigate what happens when metal oxides are added to acids. They make

predictions and look for evidence that a reaction has happened.Core (Extension), Help


E5aActivity

CoreOxides and acids

Metal oxides react with acids to make salts. In this experimentyou are going to carry out some reactions and look for evidencethat a reaction has happened.

Planning and predicting

1 Make a larger copy of this table and fill in the first column toshow what salt might be produced.

Obtaining evidence

2 Carry out the reactions one at a time.3 First, fill a test tube a quarter full of acid and

measure its temperature.4 Add a small amount of the solid you are testing.5 Look for evidence that a reaction is happening.

Fill in the second column of your table.


1 Decide whether or not a reaction happened ineach test tube.

2 What evidence shows a reaction happening?

3 Write word equations for two of the reactions thathappened during this investigation.

4 Zinc chloride can be made by reacting zinc metal, zinc oxide orzinc carbonate with hydrochloric acid. Suggest reasons why it ismore difficult to see the reaction happening if zinc oxide is used.


Oxide and acid Predicted name of salt Evidence that a reaction produced happens

copper oxide andnitric acid

zinc oxide andhydrochloric acid

copper oxide andsulphuric acid

magnesium oxide andhydrochloric acid

thermometer

spatula of oxide

acid

Wear eyeprotection.

Wash off allsplashes onthe skin

with waterimmediately and take care whenhandling acids.

Extension


E5aActivity

HelpOxides and acids

Use these tables to record your predictions and observations.

Predicting

1 Use the salt names below to help you fill in the first column ofthe table.

copper sulphate

zinc chloride

copper nitrate

magnesium chloride

Obtaining evidence

2 Use the questions below to help you look for evidence that areaction is happening. Fill in the second column of your table.

� What happens to the solid?

� Do you see any changes in the solution?

� Is there any temperature change?


Oxide and acid Predicted name of salt Evidence that a reaction made happens

copper oxide andnitric acid

zinc oxide andhydrochloric acid

copper oxide andsulphuric acid

magnesium oxide andhydrochloric acid


E5bTeacher

activity notesUses of salts

Running the activityPupils work either individually or as a group to work out how to place correctlythe cut outs. The final version can be stuck into their books.

Core: Pupils match names, uses and formulae.

Extension: Pupils design their own table to show the elements in each salt andclassify each element as a metal or non-metal.

ICT opportunitiesPupils could search the Internet for images to show uses of salts to print off andcontribute to a class display.

AnswersCore:

Barium meal: picture of X-ray: BaSO4Soldering: picture of circuit board: ZnCl2Contact lenses: picture of eye and lens: NaClPhotography: picture of camera and negative: AgBrFertiliser: picture of tractor: KNO3

Extension:


Type Purpose DifferentiationPaper Pupils learn the uses of some salts by a matching exercise involving the name, use and

formula of several salts.Core (Extension)

Name Formula Metal elements Non-metal elements

Barium sulphate BaSO4 barium sulphur, oxygen

Zinc chloride ZnCl2 zinc chlorine

Sodium chloride NaCl sodium chlorine

Silver bromide AgBr silver bromine

Potassium nitrate KNO3 potassium nitrogen, oxygen


E5bActivity

CoreUses of salts


Barium meal KNO3

Hospital patients swallow barium sulphate before they have a stomach X-ray.This shows up very clearly on the X-ray.

Soldering AgBr

Zinc chloride is used to help solder electronic components to circuit boards. It keeps the join between metals very clean.

Photography NaCl

Silver bromide is usedto make photo film. It goes dark when light hitsit to make a negative.

Contact lenses ZnCl2Sodium chloride dissolvesin water to make ‘salinesolution’. This is used toclean and store contact lenses.

Fertiliser BaSO4

Farmers add potassiumnitrate to soil in their fields.This makes crops growfaster and bigger.

2 Make a table showing what elements each salt contains.Show whether each element is a metal or a non-metal.

Many things that we use every day contain metal salts. In this activity you will be learning about the uses and formulae of some useful salts.

1 Cut out the boxes below. Match each description with a picture and a formula and stick them into your book.

Description Picture Formula

Extension


E5cTeacher

activity notesInvestigate: Making salts

Running the activityThis activity develops investigative skills in preliminary trialling, planning and evaluating. Itis not intended that pupils handle numerical variables in carrying out this activity, but theyshould measure and present the quantities of acid they use and the mass of salt they make.

Give pupils the briefing cards. These are graded at Help, Core and Extension (see below).Pupils should carry out preliminary reactions on a test-tube scale. They will need to look backin their notes to see how they prepared sodium chloride and copper sulphate to help themdevise a method for their preparation. Stress to pupils that their method needs to clearly statewhat quantity of acid they intend to use and needs also to cover the safety precautionsthey will take.

Core: Pupils are given a choice of two metal compounds to use. They need to decide whichone to use before they start their detailed planning (if different groups choose differentcompounds, any differences in yield of salts can be used later in plenary discussions). Corepupils can either plan their method by looking back at their books or, if time is tight, can usethe Help cards to support their planning.

Help: Pupils are given a single reaction. They need to sequence their method using theavailable Help cards and to decide on suitable quantities to use. The Help cards should begiven to the pupils already cut out, so that they work out the sequence of the investigationthemselves.

Extension: Pupils need to decide what acid to use and to plan the more demanding methodusing indicator to show neutralisation point. These pupils should not use the Help cards –pupils will need to look back at, and adapt, their method for making sodium chloride(Activity E2a). They should include a word equation in their report.

Expected outcomesPupils make a sample of salt and have a mass value for the quantity of the salt they make.

PitfallsCheck that the amounts of acid the pupils are proposing to use are reasonable.

Safety notesMost 0.4 mol/dm3 acids are classified as ‘irritant’. Most metal salts are harmful. Care needs tobe taken and any splashes on the skin should be washed off with water immediately. Eyeprotection should be worn.

AnswersCore:

1 Some salt will be left on all ‘wet’ apparatus e.g. reaction beaker, filter funnel. This losscould be minimised by rinsing these with water and adding the water to the evaporatingdish. The residue on the filter paper could be similarly washed to flush out any salt. Anyglass rods taken out of the solution (e.g. for pH testing) also remove small amounts of salt.More able pupils may suggest the use of a pH meter instead to minimise losses.

2 Cleanliness of all apparatus and of person making salt (washing hands etc). Traces of someof the reactants may still be mixed with the salt and these are very difficult to remove.


Type Purpose DifferentiationPractical Pupils plan a method for making a salt. They carry out their method and record

the yield.


Core, HelpResource (C, H, E)

E5cTechnician

activity notesInvestigate: Making salts


Note: different groups will need different substances, the chemicals named will be needed across the class.

� test tubes, rack, dropping pipettes, spatulas, glass rods� 0.4 mol/dm3 hydrochloric and sulphuric acid, sodium hydroxide, potassium hydroxide� copper oxide, copper carbonate, zinc carbonate, magnesium oxide, magnesium carbonate,

copper, zinc� Universal indicator paper and charts, white tile� beaker, evaporating dish and beaker suitable for water bath, filter funnel and paper, Bunsen,

tripod, gauze, mat

For Extension:

� 0.8 mol sodium hydroxide. This is to ensure equal quantities of acid and alkali can be used. (It isideal to test it out before the lesson.)

For your informationRunning the activityThis investigation develops investigative skills in preliminary trialling, planning and evaluating. It isnot intended that pupils handle numerical variables in carrying out this activity, but they shouldmeasure and present the quantities of acid they use and the mass of salt they make.

Give pupils the briefing cards. These are graded at Help, Core and Extension (see below). Pupilsshould carry out preliminary reactions on a test-tube scale. They will need to look back in theirnotes to see how they prepared sodium chloride and copper sulphate to help them devise a methodfor their preparation. Stress to pupils that their method needs to clearly state what quantity ofacid they intend to use and needs also to cover the safety precautions they will take.

Core: Pupils are given a choice of two metal compounds to use. They need to decide which one touse before they start their detailed planning (if different groups choose different compounds, anydifferences in yield of salts can be used later in plenary discussions). Core pupils can either plantheir method by looking back at their books or, if time is tight, can use the Help cards to supporttheir planning.

Help: Pupils are given a single reaction. They need to sequence their method using the available Helpcards and to decide on suitable quantities to use. The Help cards should be given to the pupilsalready cut out, so that they work out the sequence of the investigation themselves.

Extension: Pupils need to decide what acid to use and to plan the more demanding method usingindicator to show neutralisation point. These pupils should not use the Help cards – pupils will needto look back at, and adapt, their method for making sodium chloride (Activity E2a). They shouldinclude a word equation in their report.

Expected outcomesPupils make a sample of salt and have a mass value for the quantity of the salt they make.

PitfallsCheck that the amounts of acid the pupils are proposing to use are reasonable.

Safety notesMost 0.4 mol/dm3 acids are classified as ‘irritant’. Most metal salts are harmful. Care needs to betaken and any splashes on the skin should be washed off with water immediately. Eye protectionshould be worn.


Type Purpose DifferentiationPractical Pupils plan a method for making a salt. They carry out their method and record

the yield.Core, HelpResource (C, H, E)


E5cActivity

CoreInvestigate: Making salts

You are going to make a salt. You will be given a briefing cardshowing information about the salt you will make. You needto carry out test-tube trials to choose the best method formaking your salt.

Planning and predicting

1 Look at the Briefing Card for the salt you will make. Try out the reaction or reactions in test tubes as apreliminary trial. For the test-tube trial use a quarter of a test tube of acid and a small amount of solid.

2 Use the trial test-tube results to help you plan how you willmake your salt. Look back in your book to find a similarexperiment that you have done before. Use this to help youdecide on quantities and method.

3 Write a plan to show how you will make your salt.

Obtaining evidence and presenting the results

4 Carry out your plan.5 Record how much acid you used and weigh the salt to find

out how much salt you made. Show your readings clearlyusing a table. Keep your salt to show to other groups.

Evaluating

1 Do you think you ‘lost’ any salt during your investigation?How could you adapt your method to make sure you madethe maximum amount of salt from the acid you started with?

2 Suppose you were making your salt to use in a medicine. Howcould you adapt your method to make sure your salt was aspure as possible?


Wear eyeprotection.

Wash off anysplashes ofacids or

solutions on the skinimmediately with water.

Think about ...

� Does the reactionwork?

� Is it easy to see whenthe reaction stops?


E5cActivity

HelpInvestigate: Making salts

Reacting metal oxides and carbonates with acids

1 Put 20 cm3 acid in the beaker.

2 Add your metal oxide or metalcarbonate, a spatula at a time.

3 Stop adding when you can see no more changes.

Filtering

1 Set up your filter using a funneland filter paper.

2 Filter your mixture and collect thesolution in an evaporating dish.

Evaporating

1 Heat your solution gently over a water bath.

2 Stop heating when you can see crystalsappearing.

3 Leave your dish to cool.


metal oxideor metal carbonate

acid

salt mixturefilter paper

funnel

evaporating dish

evaporating dish

water


E5cActivityResourceInvestigate: Making salts

Briefing Cards


1 HelpSalt name: Copper chlorideSuggested method: Add copper carbonate to hydrochloric acid.(Use the Help Cards to help you plan your method.)

2 HelpSalt name: Zinc sulphateSuggested method: Add zinc carbonate to sulphuric acid.(Use the Help Cards to help you plan your method.)

3 CoreSalt name: Magnesium chlorideSuggested method: Either react magnesium oxide with hydrochloric acid orreact magnesium carbonate with hydrochloric acid.(You need to carry out test-tube trials to decide which method to use.)

4 CoreSalt name: Copper chlorideSuggested method: Either react copper oxide with hydrochloric acid or reactcopper carbonate with hydrochloric acid.(You need to carry out test-tube trials to decide which method to use.)

5 ExtensionSalt name: Sodium sulphateSuggested method: React sodium hydroxide solution (an alkali) with a suitable acid.(You need to choose which acid to use and decide how you will use an indicatoror pH sensor to tell when you have exactly neutralised the sodium hydroxide.)

6 ExtensionSalt name: Potassium chlorideSuggested method: React potassium hydroxide solution (an alkali) with asuitable acid.(You need to choose which acid to use and decide how you will use an indicatoror pH sensor to tell when you have exactly neutralised the sodium hydroxide.)



E1 PlenariesWhat is a metal?

Review learning� Pupils work in groups to brainstorm a list of metal

properties. Help them to get started by modelling anexample e.g. ‘metals are usually grey’, ‘metals are shiny’ etc.

� Ask pupils how you could use their list to tell the differencebetween a piece of metal and a piece of wood, glass orplastic. Discuss how electrical conductivity can be used todistinguish metals from other materials.

Sharing responses� Pupils look at their work for Activity E1b. Discuss reasons

for presenting data using graphs, e.g. patterns are moreeasily seen, metals that have very different properties aremore easily identified, some people understand charts moreeasily than numbers, charts are more visually appealing.

� Pupils feedback on their group discussions about the uses ofthe metals. Choose a different group to discuss eachexample. Ask other groups to suggest additional points thatarose in their group discussion.

Group feedback� Write the sentences below on the board. Pupils use them as

basis for group discussion on the similarities and differencesbetween metals.

� Pupils need to think about the range of properties of metalse.g. colour, melting points, conductivity etc. They may‘look ahead’ by discussing that different metals havedifferent corrosion resistances.

Word game� Pupils match words to their descriptions. They will have

met the words in this lesson.

Looking ahead� Write the words ‘Gold’, ‘Copper’ and ‘Iron’ on the board.

Show the photos of the metals and ‘fool’s gold’. Ask pupilsto brainstorm how you could tell one metal from another.Place this into context by telling them that ‘fool’s gold’looks like gold but actually contains iron and copper. Ask them to go beyond the appearance (which can bedeceptive) to suggest more reliable and sophisticated idease.g. hardness/melting points/checking physical propertiesagainst data book values.

� Pupils discuss what would happen if a lump of each metalwas buried in the garden for 10 years. This looks ahead towork on chemical properties of metals in coming lessons.

Sentences1 Metals have similar properties to

each other, for example...

2 Metals have different properties fromeach other, for example...

➔ Pupil sheet



Review learning

Pupils work in groups tolist metal properties.

Sharing responses

Pupils feed back to whole group the outcomes of Activity E1b, and discuss reasons for using graphs to process data.

Group feedback

Sentence completionby whole group onboard.

Word game

Matching exercise tocover main points ofthe lesson.

Looking ahead

Pupils discuss how to identifygold, copper and iron andspeculate on their reactivity.Catalyst Interactive Presentations 3

E-Plenaries.qxd 01-Apr-04 11:04 AM Page 1

E1 PlenariesWhat is a metal?


electricity

aluminium

iron

melting point

element

All metals conduct this.

This metal is used to make steel for cars, bridges and machinery.

This is the temperature that metalschange from solids to liquids.

A metal is this if it contains all the same type of atoms.

This metal conducts electricity almost as well ascopper. It is used for overhead electricity cables.

electricity

aluminium

iron

melting point

element

All metals conduct this.

This metal is used to make steel for cars, bridges and machinery.

This is the temperature that metalschange from solids to liquids.

A metal is this if it contains all the same type of atoms.

This metal conducts electricity almost as well ascopper. It is used for overhead electricity cables.

Sheet 1 of 1

PlenariesE1 What is a metal?

Word game

Word game




E2 PlenariesSalt on the roads

Review learning� Read out the statements about making salts on the teacher sheet and

ask pupils to decide if the statements are true or false.

Sharing responses� Pupils combine groups so that two groups make a larger group. They

compare their equations from Activity E2b.

� Pupils feed into a whole-class discussion any differences in responsesbetween the groups.

Group feedback� Ask pupils to put their finished crystals from Activity E2a on the

front bench. Also have commercial salt crystals on show (preferablyof varying sizes). Give pupils time to look at the display and thenfeed into whole class discussion reasons for the different appearancesof the crystals.

� Ideas include, purity (due to method), quantity made (amount ofstarting materials and care with method), amount of solution left(heating time), size of crystals (crystals are smaller if they form faster).Pupils can think about how salt for human consumption has to passrigorous quality control tests.

Word game� Pupils solve anagrams relating to key lesson points.

� Then pupils make up their own to test each other.

Looking ahead� The question can be set for individuals or groups to consider and

suggest answers to. They then share responses with other pupils.Make it clear that they may not know the answers and need tosuggest their ideas.

� Suggestions can be summarised and recorded in the Pupils’ books toreconsider in future lessons.

� If they are slow with ideas, suggest considering the effect of acid oneverything in sight – what would be affected? They may suggestskin/people, metals, some rocks. They need to be steered away from‘everything’ – acids do not attack glass or plastics, which is why theycan be stored safely in these materials (road tankers carrying acids aresometimes glass-lined).

➔ Teacher sheet

Equipmentdisplay of commercial saltcrystals e.g. table salt; rocksalt; ‘sea salt’ larger crystals onevaporating dishes or Petridishes on teacher’s bench

➔ Pupil sheet

QuestionWhat else do acids react with?


Review learning

True/false game.

Sharing responses

Groups combine to discussoutcomes of Activity E2b.

Group feedback

Groups compare salt crystals from Activity E2a with other groups and with commercial crystals.

Word game

Anagram activity.

Looking ahead

Pupils suggest whatelse acids react with.



Review learningTeacher sheet

Read out the statements below and ask pupils to answer true or false.


Statement True/False

1 Salt is used mainly for flavouring food. F

2 If you make a salt using hydrochloric acid, Tthe salt will be a chloride.

3 If you filter a solution of salt, the salt stays Fon the filter paper.

4 The best way to make salt crystals is to boil Fsalty water until it is dry.

5 Neutralising an acid makes a salt. T

6 A pH meter can be useful when you are Tmaking a salt.



Word game

1 These sentences contain words with jumbled letters. Work out what the word should be.

The chemical name for the salt we put on food is DUSIOM LDHICROE.When a base reacts with an acid, the acid is UEDNERTSIAL.Strong KAASLIL are pH 14.

2 Make up some of your own sentences containing words with jumbled letters, aboutideas from this lesson. Give them to another group to work out.

Sheet 1 of 1

Sheet 1 of 1


PlenariesE2 Salt on the roads

Word game





Sheet 1 of 1

PlenariesE2 Salt on the roads

Word game







E3 PlenariesAcids attack metals

Review learning� Read questions. Allow pupils time to confer to produce

a ‘group version’ of the answers.

� Use plenary discussion to make a class version of thecorrect answers.

Sharing responses� As a whole class ask pupils to brainstorm a list of

similarities and differences in the way zinc, copper andmagnesium react with acids.

� Put their ideas into context by asking them why iron,rather than either magnesium or copper is used to makecars (they may need prompting to remember fromlesson E1 that iron is much more abundant, andtherefore cheaper, than copper).

Group feedback� Pupils combine groups so that two groups make a larger

group. They compare their answers to 3 from ActivityE3a to see where they agree or differ.

� A spokesperson from each group feeds into a wholeclass plenary to show areas of agreement anddifferences.

Word game� Give pupils the list of answers. Ask them to devise

questions to result in each answer.

� Ask pupils to swap their questions to see if they cananswer each others.

Looking ahead� Ask pupils to consider the experiment about tin cans

from Activity E3b. Ask them to work as a group to makea list of what they think they will observe when theylook at their experiment next lesson. Encourage them tolist observations, such as colour changes, rather thanmore general statements, such as ‘it will react’.

Questions or clues1 This gas pops when lit.

2 This salt is made when magnesiumreacts with hydrochloric acid.

3 When we see this we know that a gas is being made.

4 What acid do you need to use tomake a sulphate?

5 This metal does not react with diluteacids.

6 What is the pH of an acid?

Answers1 hydrogen 2 magnesium chloride3 bubbles/fizzing 4 sulphuric acid 5 copper (accept silver or gold too)6 1-6/less than 7

➔ Pupil sheet


Review learning

Quick quiz.

Sharing responses

Whole-class discussion ofsimilarities and differences inthe reactions from Activity E3a.

Group feedback

Pupils work as groups todiscuss Activity E3aQuestion 3.

Word game

Write a question game.

Looking ahead

Pupils predict the outcomesof Activity E3b.


E3 PlenariesAcids attack metals

Word game

1 Work in pairs to make up some questions that would givethese answers.

2 Swap your questions with another pair and see if you cananswer each others’ questions.

Sheet 1 of 1

Sheet 1 of 1


PlenariesE3 Acids attack metals

Word game

1 Work in pairs to make up some questions that would givethese answers.

2 Swap your questions with another pair and see if you cananswer each others’ questions.


hydrogen

magnesium chloride and water

copper

fizzing neutralised

iron chloride

hydrogen

magnesium chloride and water

copper

fizzing neutralised

iron chloride



E4 PlenariesAcids attack carbonates

Review learning� Pupils work in small groups. Ask them to look at their work

from this lesson and compile three (or more) questions toask another group.

� Combine two groups into larger groups. They test eachother on the questions they have written.

Share responses� Whole-class discussion to brainstorm what changes were

seen during Activity E4a, including maximum temperaturechanges observed.

� Ask the pupils, ‘Which observations show that a chemicalchange is happening?’ Focus discussion of ideas of newproducts and energy changes.

� Ask the pupils, ‘Why did different groups make slightlydifferent observations?’ Focus on how the instructions forthe experiment could be adapted to make more reliableobservations between groups e.g. controlling the size ofspatulas added, controlling the time of each addition,taking averages etc.

Group feedback� Pupils combine groups so that two groups make a larger

group. Ask them to compare the outcomes of Activity E4b.A group spokesperson feeds back to the class either thegroup version of the correct answers, or highlights wheredisagreements occur.

Word game� Pupils complete the Cloze activity on the Pupil sheet in

pairs.

Looking ahead� Brief pupils about using acid leaching to extract metal

compounds (see Teacher sheet).

� Show pupils samples of some minerals and ask them tosuggest what compounds are made during acid leaching.

➔ Pupil sheet

Answers: acids; magnesium chloride;carbon dioxide; sulphuric acid;chlorides; nitric

➔ Teacher sheet



Review learning

Group team quiz.

Sharing responses

Whole-class discussion to feedbackoutcomes of Activity E4a.

Group feedback

Groups compare responses to Activity E4b.

Word game

Pupils work in pairsto complete Clozesentences.

Looking ahead

Pupils think about what salts would be made when minerals are‘leached’ using acids. Catalyst Interactive Presentations 3



Word game

Work in pairs to work out the missing words in the sentencesbelow.

Metal carbonates react with to make salts.

For example, magnesium carbonate reacts with hydrochloric acidto make a salt called . The magnesiumcarbonate fizzes because a gas is made at the same time.

This gas is called .

Different acids make different salts. acid makessulphates.

Hydrochloric acid makes and acidmakes nitrates.

Sheet 1 of 1

Sheet 1 of 1


PlenariesE4 Acids attack carbonates

Word game

Work in pairs to work out the missing words in the sentencesbelow.

Metal carbonates react with to make salts.

For example, magnesium carbonate reacts with hydrochloric acidto make a salt called . The magnesiumcarbonate fizzes because a gas is made at the same time.

This gas is called .

Different acids make different salts. acid makessulphates.

Hydrochloric acid makes and acidmakes nitrates.




Looking ahead

Teacher sheet

� Tell pupils that many metals occur in nature as metal compounds. One wayof getting the valuable metal compound out of the mineral is by ‘leaching’using acid. This involves reacting the metal compound in the mineral withacid so it forms a solution that can be washed out of the waste rock (this isused even on old spoil heaps).

� Show pupils some mineral samples and write their names on the board. Askthem quick questions about the acid leaching to encourage them to thinkabout the names of the salts that would be made. More able pupils shouldunderstand that the metal compound involved does not matter – the nameof the salt depends on the metal in the compound and the acid only (thiswill feed in to work on oxides next lesson).

Examples of questions to ask:

1 If I leached copper compounds using sulphuric acid, I would make... .

2 If I leached lead compounds using nitric acid, I would make...

3 If I leached zinc compounds using hydrochloric acid, I would make...

4 What would you see if you poured sulphuric acid on a mineralcontaining copper carbonate?




E5 PlenariesAcids and metal oxides

Review learning� Pupils use cards to choose different reactants to make

the same salt. Give them the cards on the pupil sheetand ask them to choose substances that could be reactedto make copper sulphate, calcium chloride andmagnesium sulphate.

� Ask more able pupils ‘When making copper sulphate,why is it easier to use copper carbonate rather thancopper or copper oxide?’ (copper does not react withdilute acids, copper oxide does not fizz so it is difficultto tell when the reaction has stopped).

Sharing responses� Ask a spokesperson from each group to discuss what

they found out from Activity E5a. Each group talksabout a different reaction. They should summarise theirevidence for deciding whether or not a salt was made ineach case.

� Other groups can then challenge them or volunteerinformation about any other observations or points thatthey have left out.

Group feedback� Pair two small groups into a larger group so that they

can compare their solutions to Activity E5b.

� Each small group then chooses a spokesperson who hasto talk to their ‘paired’ group about ‘Uses of Salts’ forone minute without looking at the worksheet. Eachpaired group gives their talk.

Word game� Give pupils a completed crossword. They write clues to

the crossword. Groups can combine to compare theclues that they write to decide which clues are ‘best’.

Looking back� Pupils revise and consolidate knowledge for the unit.

They can use the Unit map, Pupil checklist or the Testyourself questions.

➔ Pupil sheet

➔ Pupil sheet

➔ Unit map

➔ Pupil checklist

➔ Test yourself


Review learning

How many different wayscan you make a salt?

Sharing responses

Group spokesperson feeds backoutcomes of Activity E5a.

Group feedback

Groups combine to discussActivity E5b.

Word game

Writing crossword clues.

Looking back

Pupils revise and consolidateknowledge from the unit.



Review learning

Sheet 1 of 1

Sheet 1 of 1


PlenariesE5 Acids and metal oxides


magnesiumcopper oxide

magnesiumcarbonate

sulphuric acid

hydrochloricacid

magnesiumoxide

calciumhydroxide

calciumcarbonate

calcium oxide

coppercarbonate

Review learning

magnesiumcopper oxide

magnesiumcarbonate

sulphuric acid

hydrochloricacid

magnesiumoxide

calciumhydroxide

calciumcarbonate

calcium oxide

coppercarbonate



Word game

Write clues for the completed crossword.

Clues

1 across (6)

2 across (9)

5 across (5)

6 across (6,7)

7 across (8)

1 down (10)

3 down (4)

4 down (4)

Sheet 1 of 1

Sheet 1 of 1


PlenariesE5 Acids and metal oxides


CIRTIN

M A G

1

E2 3

N E S I U M4

C5O X I D E

D

L

A T

R

A

L

T

6 C A R B O N D I O X I D E

S

EH7 Y D R O G N

Word game

Write clues for the completed crossword.

Clues

1 across (6)

2 across (9)

5 across (5)

6 across (6,7)

7 across (8)

1 down (10)

3 down (4)

4 down (4)

CIRTIN

M A G

1

E2 3

N E S I U M4

C5O X I D E

D

L

A T

R

A

L

T

6 C A R B O N D I O X I D E

S

EH7 Y D R O G N



E5 PlenariesInvestigate: Making salts

Review learning� Ask pupils to put their finished salt on the front bench with a label

giving its name.

� Pupils look at the salts that different groups have made.

� Ask pupils what reasons they can give for the different appearance ofthe salts on display (e.g. quantity (amount of acid used), colour (metalin the salt), size of crystals etc.)

Group feedback� Each group prepares a poster or OHT to tell the whole class how they

carried out their investigation. Pupils may need help to design theflow chart.

� A spokesperson from each group feeds back to the whole class bygiving a short oral presentation based on their poster (see Pupil sheetfor framework).

� If time is tight, the posters could be used for display, without oralfeedback, or each spokesperson could speak briefly without preparinga poster.

Analysing� Ask pupils to volunteer their ideas about how the yield and purity of

their salt could be improved ( 1 and 2 on the Activity sheet). Theproblem solving Pupil sheet from the starter activity could be usedhere.

� If different groups have made the same salt, their yields can becompared and discussed.

� Contextualise this discussion by talking about how important it is tomake maximum yields in chemical factories to increase profitability.Wasting valuable, raw materials (e.g. in the manufacture of fertilisersor medicines) is costly, and purity is necessary in the preparation ofsalts for human consumption (e.g. food and medicines.)

Evaluating� Ask pupils to brainstorm ideas to draw a factory-sized version of a salt

making process (e.g. big reaction vessel with pipes to take acid in,hoppers to take solid carbonate in, tips into big filter, pipes toevaporating pans). This can be fun rather than technical.

� Ask them what ‘capital costs’ would be involved – what equipmentwould need to be bought? What would the running costs be (e.g. fuel,wages, raw materials)?

➔ Pupil sheet


Review learning

Teacher-led review about thetype of salt produced.

Group feedback

Groups describe theirinvestigation to the class.

Analysing

Teacher-led discussion on improvingyield and purity.

Evaluating

Teacher-led brainstorm to think aboutscaling up salt making to an industrialscale.


E5 PlenariesInvestigate: Making salts

Group feedback

Choose a spokesperson from your group. Make a poster or anOHT to tell the rest of the class about your investigation. Yourposter needs to show:

1 The name of your salt.2 How you made your salt. Don’t forget to include:

� the amounts of substances you used� each step of your method.You can show this either by writing numbered ‘steps’ or bydesigning a flow chart.

3 Anything you feel did not work as well as you hoped.4 Anything you feel worked very well.

Sheet 1 of 1

Sheet 1 of 1


PlenariesE5 Investigate: Making salts

Group feedback

Choose a spokesperson from your group. Make a poster or anOHT to tell the rest of the class about your investigation. Yourposter needs to show:

1 The name of your salt.2 How you made your salt. Don’t forget to include:

� the amounts of substances you used� each step of your method.You can show this either by writing numbered ‘steps’ or bydesigning a flow chart.

3 Anything you feel did not work as well as you hoped.4 Anything you feel worked very well.



E1 SpecialsWhat is a metal?

1 Use some of these words to fill in the gaps.

a Metals let heat flow through them easily because they

are .

b Metals let electricity flow easily through them because

they are .

c When metals are polished they are .

d Metals do not break easily. They are .

e A few metals, including iron, are .

f Most metals are at room temperature.

2 Draw lines from the material to its use and to why it is used in that way.


Gold isused ...

Aluminiumis used ...

Copper is used ...

Iron isused ...

Plastic isused ...

... to coverelectrical wires ...

... to makeelectrical wires ...

... to makejewellery ...

... to makesaucepans ...

... to makebridges ...

... because it is agood heat conductor.

... because it is anelectrical conductor.

... because it is strong.

... because it stays shiny.

... because it is anelectrical insulator.

shinyelectrical conductors heat insulators

electrical insulators weak liquids magnetic solids

able to be shaped heat conductors strong gases

E-Specials.qxd 12-May-04 3:54 PM Page 1

E2 SpecialsSalt on the roads

1 Use these words to fill in the gaps.

a Bases acids. This means they each other out.

b Bases that dissolve in water are called .

c When an acid and an alkali or a base neutralise each other,

a and are made.

d A strong acid has a pH of .

e A strong alkali has a pH of .

f A neutral solution has a pH of .

2 Use these words to complete the word equations.

asodium

+hydrochloric

→ + waterhydroxide acid chloride

bzinc

+hydrochloric

→ + waterhydroxide acid

c +hydrochloric

→calcium

+ waterhydroxide acid chloride

diron

+ →iron

+hydroxide acid chloride


watercancel seven one neutralise

alkalis fourteen salt

chloride

calcium

hydrochloric zinc

water sodium


E2 SpecialsSalt on the roads (continued)

3 Here are the instructions for making the salt sodium chloride. They have been jumbled up.

a Write numbers in the boxes to give the correct order.

b What is the name of the acid used?

c What is the name of the alkali used?

d The reactants are called and

.

e The salt made is called .

f The products of the reaction are and

.


Mix sodium hydroxide and hydrochloricacid.

Measure out25 cm3 sodiumhydroxide. Measure out25 cm3

hydrochloric acid.

AC

ID

Leave to cooland let crystalsgrow.

Evaporate mostof the water.


E3 SpecialsAcids attack metals

1 Write true or false for each sentence.

a All acids have hydrogen in them.

b Some metals react with acids to make oxygen gas.

c Hydrogen gas pops with a lighted splint.

d Acids corrode some metals. This means that they ‘eat’

away the metals.

e When a metal reacts with an acid, a salt and hydrogen

gas are made.

2 Clara did an experiment to make crystals of magnesium sulphate. Here is what she did, but it is all jumbled up.

a Put Clara’s account into the correct order by writing number 1, 2, 3 or 4 in each box.


I left the solution to cool. I could see white crystals of the saltin the evaporating basin.

I put silvery magnesium ribbon into the sulphuric acid. It fizzedand disappeared. I added more pieces of magnesium until thefizzing stopped and there was some magnesium left.

I poured the mixture into a filter paper to get rid of themagnesium.

I heated the solution of magnesium sulphate until nearly all thewater had evaporated.


E3 SpecialsAcids attack metals (continued)

b What gas is made when magnesium reacts with sulphuric acid?

Circle the correct answer.

oxygen hydrogen carbon dioxide

c Look at what Clara did and then fill in the gaps in this word equation.

+ → +acid sulphate

3 Use these words to complete the word equations.

a iron +hydrochloric

→ + hydrogenacid chloride

b zinc +sulphuric

→ +acid sulphate

c tin + →tin

+acid chloride

d + →magnesium

+ hydrogenacid chloride


hydrogenhydrochloric zincmagnesium iron


E4 SpecialsAcids attack carbonates

1 Look carefully at this cartoon.

Use the cartoon to help you answer these questions.

a The gas made when carbonates neutralise acids is called

.

b This gas turns limewater .

ccopper

+hydrochloric

→ + water +carbon

carbonate acid dioxide

dcalcium

+hydrochloric

→ + water +carbon

carbonate acid chloride dioxide

2 Look at this word equation.

magnesium+

sulphuric→

magnesium+ water +

carbon carbonate acid sulphate dioxide

Write true or false for each sentence.

a Carbon dioxide is one of the reactants.

b There are three products in the equation.

c The salt made is called magnesium chloride.

d Magnesium sulphate and sulphuric acid are the reactants.


Limestone iscalcium carbonate.

Carbonatesneutralise acids.

They makecarbon dioxide gas.

Carbon dioxide turnslimewater milky.


E5 SpecialsAcids and metal oxides

1 David heated copper oxide with sulphuric acid to make crystals of copper sulphate. He missed out some words in his method. Use these words to fill in the gaps. You may need to use some words more than once.


I put some black copper powder into the

acid. Then I it. The black powder

reacted and disappeared. The acid turned blue. I added more

black powder until no more would .

I then poured the mixture into a . The blue solutioncame through.

I heated the blue solution to evaporate some of the .

I left it to cool and blue crystals of sulphate were left.

The word equation for this reaction is:

copper+ → + wateracid sulphate

2 Look carefully at these word equations. Each one has a mistake in it.

Circle each mistake. Then write out each equation correctly. The firstone has been done for you.

a copper oxide + sulphuric acid → copper chloride + water

b zinc oxide + sulphuric acid → magnesium sulphate + water

c iron oxide + hydrochloric acid → iron sulphate + water

copper oxide + sulphuric acid → copper sulphate + water

waterfilter paper copper oxide

heated dissolve sulphate sulphuric


E Specials answersReactions of metals and metalcompounds

E1 What is a metal?1 a heat conductors

b electrical conductorsc shinyd stronge magneticf solids

2 Iron is used … to make bridges … because it isstrong.Plastic is used … to cover electrical wires …because it is an electrical insulator.Gold is used … to make jewellery … because itstays shiny.Aluminium is used … to make saucepans …because it is a good heat conductor.Copper is used … to make electrical wires …because it is an electrical conductor.

E2 Salt on the roads1 a neutralise, cancel

b alkalisc salt, waterd onee fourteenf seven

2 a sodiumb zinc chloridec calciumd hydrochloric, water

3 a Numbers in boxes – 2, 1, 4, 3.b hydrochloric acidc sodium hydroxided hydrochloric acid, sodium hydroxidee sodium chloridef sodium chloride, water

E3 Acids attack metals1 a true

b falsec trued truee true

2 a Numbers in boxes – 4, 1, 2, 3.b hydrogenc magnesium + sulphuric acid →

magnesium sulphate + water3 a iron

b zinc, waterc hydrochloric, hydrogend magnesium, hydrochloric

E4 Acids attack carbonates1 a carbon dioxide

b milkyc copper chlorided calcium

2 a falseb truec falsed false

E5 Acids and metal oxides1 oxide, sulphuric, heated, dissolve, filter paper,

water, copperWord equation: copper oxide + sulphuric acid →copper sulphate + water

2 b zinc oxide + sulphuric acid → zinc sulphate +water or magnesium oxide + sulphuric acid →magnesium sulphate + water

c iron oxide + hydrochloric acid → iron chloride + water or iron oxide + sulphuricacid → iron sulphate + water


Spe Answers.qxd 6/23/2004 9:19 AM Page 5

E1 Homework

HELP

1 The list shows some properties of materials.

good electrical conductorinsulatorcan be made into wiresgood thermal conductorbreaks easilymelts above 25oC

a Give three properties of metals.b Give two properties of non-metals.

2 Four uses of metals and reasons why they are used are shownbelow. Write down each use and match it to the reason for itsuse.


E1 What is a metal?

Sheet 1 of 2

Uses

A Copper is used in electrical wiringB Mercury is used in thermometersC Gold is used for jewelleryD Aluminium is used for drinks cans

Reasons

1 because it looks attractive and does not tarnish.2 because it can be easily pressed into shape.3 because it expands a lot when it is heated.4 because it conducts electricity very well.

CORE

3 a Draw a labelled diagram of the apparatus you would use toshow that a metal was a good conductor of electricity.

b What would you see, using your apparatus, if the followingmaterials were tested?

i plastic ii steel iii zinc iv carbon (graphite)

4 a What is true about all the atoms in a piece of tin?

b Bronze is an alloy of copper and tin. How many types of atomsdoes a sample of bronze contain?

E-Homework.qxd 17-May-04 6:30 PM Page 1

E1 HomeworkWhat is a metal? (continued)

EXTENSION

5 The table shows the melting and boiling points of some metals.

a i Which metal has the smallest temperature range asa liquid?

ii Which metal has the largest temperature range as aliquid?

b Give two reasons why tungsten is used in electric filamentlamps.

c Lead forms part of electrical solder, used for joining wires.Explain why lead can be used for this purpose but mercurycannot.

d i Which metal will need the most energy, per millionatoms, to boil it?

ii Explain your answer.

Metal Melting point (ºC) Boiling point (ºC)

Tungsten 3377 5527

Sodium 98 883

Mercury −38 356

Lead 327 1740

Iron 1533 2750

Gold 1063 2707

Aluminium 660 2467



E2

HELP

1 Copy and complete the following equations:

a acid + base → +

b sulphuric acid + magnesium oxide → + water

2 Some of the statements below are true and some are false. For eachone say whether it is true or false.

a i Hydrochloric acid makes chloride salts.

ii Strong acids have a pH value of around 14.

iii Neutralisation is not a chemical reaction.

iv Sodium chloride is in the salt they put on the roads.

b For one of the statements in part a that you thought was false writea correct statement to replace it.

CORE

3 The list shows several chemicals that can be used to make salts.

sodium hydroxide sulphuric acid iron hydroxidehydrochloric acid zinc oxide potassium hydroxide

a Write down which pair of chemicals you would use to make eachof the salts given below.

i zinc sulphate ii potassium chloride iii iron sulphate

b What other substance is made, as well as the salt, in all the reactions in part a?

c i Write a full word equation to represent the reaction betweensulphuric acid and potassium hydroxide.

ii What would be the pH value of the solution you produced, if youmixed the reactants in exactly the right amounts?

iii What is the name of the type of reaction that happens?

EXTENSION

4 The chemical formula for copper sulphate is CuSO4.

a i What is the total number of atoms shown in the formula?

ii How many different types of atoms are shown?

b i Give the names of two reactants you could mix together tomake copper sulphate.

ii Write out the full word equation for the reaction you have chosen.

c Briefly outline how you would make copper sulphate using these two reactants.

HomeworkSalt on the roads



E3 HomeworkAcids attack metals

HELP1 Tom does an experiment with some magnesium. He puts it into a

test tube with some dilute acid.a Write down two things that he would see happening.

b i What test could Tom use to see if hydrogen was being given off?

ii What would happen if hydrogen was given off?

iii Explain why this would happen.

c Copy and complete the word equation below:

magnesium + hydrochloric acid → +

d What would Tom notice if he used gold, instead of magnesium, in the acid?

CORE

2 The information describes how chromium chloride can be obtained from chromite (a chromium-containing mineral).


Chromite is extracted from amixture with sand and otherimpurities from the mine. Thisgives a reasonably pure sampleof chromium oxide. Thechromium oxide is converted

into chromium in a blastfurnace. When mixed with anacid, chromium is convertedinto chromium chloridesolution.

a What element is removed from chromium oxide in a blast furnace?

b i What products would be obtained if chromium oxide was mixedwith sulphuric acid?

ii Write a word equation to represent this reaction.

c i What acid would react with chromium to produce chromium chloride?

ii What gas would also be produced during this reaction?

iii Why would it be dangerous for workers in a chromium chlorideplant to smoke near to the reaction vessel?

d i Explain why garden ornaments that have been coated with a thinlayer of chromium might suffer damage from acid rain.

ii What do we call this type of damage to metals?


E3 HomeworkAcids attack metals (continued)

EXTENSION

3 Aluminium is quite a reactive metal. However, it often does notappear to react very easily with acids.

a Explain why aluminium is often unreactive.

b When aluminium is treated with a solution of mercurychloride its reactivity with acids can be easily seen.

i What does the mercury chloride solution probably removefrom the aluminium to make it become properly reactive?

ii Describe what you would expect to see if this reactivealuminium is dropped into some sulphuric acid.

iii Write a word equation for the reaction betweenaluminium and sulphuric acid.

4 Look at the symbol equation below.

Mg + H2SO4 → MgSO4 + H2

a What is the total number of atoms on the left of the arrow?

b How many atoms, on the right of the arrow, are metallic?



E4 HomeworkAcids attack carbonates

HELP

1 Jenny is doing an experiment with some hydrochloric acid. She addsa solid to the acid. The acid fizzes. She tests the gas with a lighted splint.It burns with a squeaky pop.

a What gas was produced in Jenny’s experiment?

b How does this tell you that the solid she used was not a metal carbonate?

c i If she had added a metal carbonate, how would shetest the gas given off?

ii What would happen in the test?

d Copy and complete the following word equation:

zinc carbonate + sulphuric acid → +

+ water

e Give two other observations that Jenny might have made that wouldshow that a chemical reaction was taking place.

CORE

2 Sodium hydrogencarbonate reacts just like sodium carbonate, whenit is mixed with acids. The sherbet centres of some sweets contain amixture of solid sodium hydrogencarbonate and solid citric acid.

a The substances involved in the sherbet reaction are:

sodium citrate sodium hydrogencarbonate watercarbon dioxide citric acid

i Write down the three substances from the list that will beproduced when sherbet is mixed in the mouth.

ii Rearrange the substances to write a word equation for thereaction between sodium hydrogencarbonate and citric acid.

b Why does the sherbet react in the mouth but not inside the sweet?

c Explain why a lighted splint put into the gas produced from sherbetwould go out.

3 Sometimes people complain about having an ‘acid stomach’.

a Explain what causes an ‘acid stomach’.

b Why would taking an indigestion tablet help to improve an ‘acid stomach’?

c The substance in the indigestion tablet is calcium carbonate. Write aword equation to show how it neutralises the stomach acid.



E4 HomeworkAcids attack carbonates (continued)

EXTENSION

4 Here is some information about some compounds:

Read the information below:


In Sweden, many lakes havebecome acidic because acidrain has fallen and drained into them. This is having asevere effect on the fish stocksin the lakes, which have fallendramatically. The Swedishgovernment want to try to

solve the problem by addingother compounds to the lakes from a helicopter. They could try adding eitherpowdered calcium carbonate or powderedsodium carbonate to the lakewater.

a Why might adding calcium carbonate or sodium carbonateto the lakes solve the problem?

b What would be formed in the lakes if

i powdered calcium carbonate was added?

ii powdered sodium carbonate was added?

c i Using the information from the start of the question, explainwhy adding too much sodium carbonate would create adifferent problem in the water.

ii Why would this not happen if too much powdered limestonewas added?

d Write down the word equation for the reaction when limestoneis added to acidic lake water.

Acid rain contains dilute sulphuric acid.

Limestone is mainly calcium carbonate.

Sodium carbonate is soluble in water.

Sulphuric acid in lakes kills fish.

Sodium carbonate solution is alkaline.

Calcium carbonate is insoluble in water.


E5 HomeworkAcids and metal oxides

HELP

1 a Write down two different correct ways in which you could finishthe sentence below.

When a metal oxide reacts with an acid ... .

b List two things you could observe that would show a chemicalreaction had happened when an acid is mixed with an oxide.

c Use the chemicals in the list below to copy and complete the wordequations. You will need to use one of them more than once.

i zinc oxide + nitric acid → +

ii copper oxide + → copper chloride +

iii + sulphuric acid → zinc sulphate +

CORE

2 Write down pairs of substances from the list below to match thename of each salt to its use. One must be used twice.

3 Cobalt oxide is an olive-green solid, which is insoluble in water. Cobaltchloride is a pink solid that dissolves in water to give a pink solution.

a Describe what you would see if excess cobalt oxide is warmed withsome hydrochloric acid solution.

b i What happens to the pH of the solution by the end of the reaction?

ii Explain why this happens.

c What forms if the cobalt oxide reacts with sulphuric acid instead ofhydrochloric acid?


zinc nitrate water hydrochloric acid zinc oxide

Epsom saltsco

controlling disease on grapevines flavouring or preserving foodcopper sulphate

as a laxative setting broken bones sodium chloride

calcium sulphateclearing snow and ice from roads


E5 HomeworkAcids and metal oxides (continued)

EXTENSION

4 The formulae of some compounds are given below.

a Write a word equation to represent the reaction that would happenbetween iron oxide and sulphuric acid.

b Use the formulae above to write the symbol equation for this reaction.

c Where does the water that is made come from?

d i What is the total number of atoms in all of the products?

ii How many different types of atoms are in the products?

e Which acid would you use if you wanted to make iron chlorideinstead of iron sulphate?


Iron oxide – FeO Iron sulphate – FeSO4

Sulphuric acid – H2SO4 Water – H2O


E1Homework

mark schemeWhat is a metal?


HELPQuestion Answer Mark

1 a Three from: good electrical conductor; can be made into wires; good thermal conductor; melts above 25 oC. 3

b Insulator; breaks easily. 2

2 a Correct combinations are: A 4; B 3; C 1; D 2. All four correct = 3 marks. Deduct 1 mark for each error. 3

Total for Help 8

COREQuestion Answer Mark

3 a Diagram contains: power supply 1bulb/buzzer/bell 1point to connect two terminals to the sample 1suitable connecting wires all in series. 1Can be a drawing or a circuit diagram.

b i Lamp does not light up/buzzer does not sound. 1

ii Lamp lights up/buzzer sounds. 1

iii Lamp lights up/buzzer sounds. 1

iv Lamp lights up/buzzer sounds. 1

4 a They are identical/all the same. 1

b Two 1

Total for Core 10

EXTENSIONQuestion Answer Mark

5 a i Mercury 1

ii Tungsten 1

b It conducts electricity. 1It has a high melting point. 1

c Lead is solid at room temperature and has a low melting point 1but mercury would not be solid at room temperature. 1

d i Tungsten 1

ii It has the highest melting point so needs the most energy to reach that temperature. 1

Total for Extension 8


E2Homework

mark schemeSalt on the roads



1 a Salt + water 2

b Magnesium sulphate 1

2 a i True 1

ii False 1

iii False 1

iv True 1

b Either: Strong acids have a pH value of around 1/Strong alkalis have a pH value of around 14. Or:Neutralisation is a chemical reaction. 1

Total for Help 8


3 a i Zinc oxide and sulphuric acid. 2

ii Potassium hydroxide and hydrochloric acid. 2

iii Iron hydroxide and sulphuric acid. 2

b Water 1

c i Sulphuric acid + potassium hydroxide → potassium sulphate + water 1Award mark for products only.

ii pH 7 1

iii Neutralisation 1

Total for Core 10


4 a i 6 1

ii 3 1

b i Copper oxide/copper hydroxide and sulphuric acid. Accept other correct combinations. 2

ii Copper oxide + sulphuric acid → copper sulphate + water Accept equations following from choice of base in part b i. 2

c Mix copper oxide with some sulphuric acid in a beaker and stir. 1Filter off unchanged copper oxide and evaporate the solution. 1



E3Homework

mark schemeAcids attack metals



1 a Bubbles/fizzing/effervescence. 1The magnesium would get smaller. Do not accept ‘disappear’. 1

b i A lighted splint. 1

ii It would burn/explode with a squeaky pop. 1

iii Hydrogen forms an explosive mixture with air. 1

c Magnesium + hydrochloric acid → magnesium chloride + water 2Underlined section is pupil response. 1 mark for each substance.

d There would be no reaction/it would not fizz, etc. 1

Total for Help 8


2 a Oxygen 1

b i Chromium sulphate and water. 2

ii Chromium oxide + sulphuric acid → chromium sulphate + water 21 mark for reactants + 1 mark for products

c i Hydrochloric acid. 1

ii Hydrogen 1

iii Hydrogen is flammable/explosive. 1

d i The acid would react with/dissolve the chromium. 1

ii Corrosion 1

Total for Core 10


3 a A protective coating of aluminium oxide forms over its surface. 1

b i It removes the protective coating. 1

ii Bubbles/fizzing/effervescence. 1The metal would get smaller. 1

iii Aluminium + sulphuric acid → aluminium sulphate + hydrogen 21 mark for reactants + 1 mark for products

4 a 8 1

b 1 1



E4Homework

mark schemeAcids attack carbonates



1 a Hydrogen 1

b They give off carbon dioxide. 1

c i Bubble it through limewater. 1

ii The limewater would have turned milky. 1

d Zinc carbonate + sulphuric acid → zinc sulphate + carbon dioxide + water 2Underscore shows the pupil’s answer.

e Two from: change colour; get warm; form a solid precipitate etc. 2

Total for Help 8


2 a i In any order: sodium citrate; water; carbon dioxide. 3

ii Citric acid + sodium hydrogencarbonate → sodium citrate + carbon dioxide + water 1

b It dissolves in water/saliva so the substances mix properly. 1

c Carbon dioxide does not allow things to burn. 1Accept equivalent responses.

3 a The stomach makes too much hydrochloric acid. 1

b It would neutralise the acid. 1

c Calcium carbonate + hydrochloric acid → calcium chloride + carbon dioxide + water 2Award 1 mark for correct reactants and 1 mark for correct products.

Total for Core 10


4 a They would neutralise the acid. 1

b i Calcium sulphate 1

ii Sodium sulphate 1

c i The excess sodium carbonate would dissolve in the water 1making it alkaline. 1

ii Limestone/calcium carbonate is insoluble 1so would not affect the water/change the pH of the water/would justsink to the bottom. 1

d Calcium carbonate + sulphuric acid → calcium sulphate + carbon dioxide + 1water



E5Homework

mark schemeAcids and metal oxides



1 a Two correct sentences e.g.When a metal oxide reacts with an acid the acid is neutralised. 1When a metal oxide reacts with an acid a salt is formed. 1Underscores are pupil’s responses.

b Changes colour; gets warm. 2

c i Zinc nitrate + water (both as products).

ii Hydrochloric acid (as a reactant) and water (as a product).

iii Zinc oxide (as a reactant) and water (as a product). Award 1 mark if water appears in all three answers as a product. Award 1 mark for the other missing substance in each equation. 4

Total for Help 8


2 Epsom salts – as a laxative. 1Copper sulphate – preventing disease on grapevines. 1Sodium chloride – flavouring or preserving foods. 1Sodium chloride – clearing snow and ice from roads. 1Calcium sulphate – setting broken bones. 1

3 a Some of the olive green solid would react/the amount of solid in the mixture would decrease. 1The solution would change colour. 1

b i It would have increased/changed from pH1 to pH7/it would have become neutral. 1

ii The cobalt oxide neutralises the acid. 1

c Cobalt sulphate 1

Total for Core 10


4 a Iron oxide + sulphuric acid → iron sulphate + water 2Award 1 mark for the reactants and 1 mark for the products.

b FeO + H2SO4 → FeSO4 + H2O 2Award 1 mark for the reactants and 1 mark for the products.

c Hydrogen from the acid and the oxygen from the iron oxide. 1

d 9 14 1

e Hydrochloric acid 1



E Test yourselfReactions of metals and metalcompounds

1 Tick the descriptions that are true.

A metal is:

a good conductor of heat strong

brittle living

a solid an electrical insulator

shiny

2 Complete the following passage by choosing from the words below to fill the gaps. Use each word not more than once only.

Most of the elements are . These are all

at room temperature, except mercury.

Most metals have melting points.

3 Complete this table about metals by filling in the empty boxes.

4 When an acid reacts with an alkali, two products are formed. What are they?

1 2

5 15 cm3 of sodium hydroxide solution are measured into a beaker. The pH is 14.

30 cm3 of the same concentration of hydrochloric acid are added, 1 cm3

at a time. The pH of the solution is measured after each addition.

a What is the pH:

i when 15 cm3 of acid have been added? pH

ii when 30 cm3 of acid have been added? pH


high liquids low metals non-metals solids

Metal Use of metal Property related to this use

copper conducts electricity

aluminium saucepans

bridges very hard

gold jewellery

Test-Qust.qxd 6/25/2004 10:32 AM Page 14

E Test yourselfReactions of metals and metal compounds(continued)

b What is this type of reaction called?

c What is the name of the salt formed during this reaction?

6 When a metal reacts with an acid, two products are formed. What are these two products?

7 Look at this list of metals.

Choose from the list a metal that:

a reacts violently with dilute hydrochloric acid.

b reacts steadily with dilute hydrochloric acid.

c does not react with dilute hydrochloric acid.

8 Complete this word equation.

magnesium + + acid

→sulphate

9 When metal carbonates react with acids, the gas carbon dioxide is produced.

Describe a test for carbon dioxide.

Test:

Result:


copper+ →

copper+ +

carbonate acid nitrate


potassium sodium zinc iron copper gold


E Test yourselfReactions of metals and metal compounds(continued)

11 a These sentences describe how you could make crystals of zinc sulphate, but some instructions have been missed out. Fill in the missing instructions.

Add some zinc oxide to dilute sulphuric acid in a test tube.

Warm the mixture in a beaker of hot water.

Evaporate some of the water by boiling the solution.

Filter to get the crystals of zinc sulphate.

b Write a word equation for the reaction between zinc oxide and sulphuric acid.

12 The table below gives the names of some salts and substances that can react to formthese salts. Fill in the empty boxes to complete the table.

13 Complete these word equations.

aaluminium

+ →aluminium

+ wateroxide acid sulphate

blithium

+nitric


c calcium +hydrochloric

→calcium

+acid

dpotassium

+hydrochloric

→ + + watercarbonate acid


Salt Substances that react together to make the salt

hydrochloric acid sodium hydroxide

copper sulphate copper oxide

magnesium nitrate magnesium carbonate

potassium sulphate sulphuric acid


ETest yourself

AnswersReactions of metals and metalcompounds

1 Tick the descriptions that are true.

A metal is:

a good conductor of heat strong

brittle living

a solid an electrical insulator

shiny

2 Complete the following passage by choosing from the words below to fill the gaps. Use each word not more than once only.

Most of the elements are . These are all

at room temperature, except mercury.

Most metals have melting points.

3 Complete this table about metals by filling in the empty boxes.

4 When an acid reacts with an alkali, two products are formed. What are they?

1 2

5 15 cm3 of sodium hydroxide solution are measured into a beaker. The pH is 14.

30 cm3 of the same concentration of hydrochloric acid are added, 1 cm3

at a time. The pH of the solution is measured after each addition.

a What is the pH:

i when 15 cm3 of acid have been added? pH

ii when 30 cm3 of acid have been added? pH 1

7

watera salt

high

solids

metals

�

�

��


high liquids low metals non-metals solids

Metal Use of metal Property related to this use

copper wires conducts electricity

aluminium saucepans conducts heat

iron or tungsten or steel bridges very hard

gold jewellery unreactive

Test-Ans.qxd 16-Jun-04 2:55 PM Page 14

ETest yourself

AnswersReactions of metals and metal compounds(continued)

b What is this type of reaction called?

c What is the name of the salt formed during this reaction?

6 When a metal reacts with an acid, two products are formed. What are these two products?

7 Look at this list of metals.

Choose from the list a metal that:

a reacts violently with dilute hydrochloric acid.

b reacts steadily with dilute hydrochloric acid.

c does not react with dilute hydrochloric acid.


magnesium + + acid

→sulphate

9 When metal carbonates react with acids, the gas carbon dioxide is produced.

Describe a test for carbon dioxide.

Test:

Result:


copper+ →

copper+ +

carbonate acid nitrate

carbonwater

nitric

Limewater turns cloudy.

Bubble the gas through limewater.

hydrogenmagnesiumsulphuric

copper or gold

zinc or iron

potassium or sodium

hydrogena salt

sodium chloride

neutralisation

dioxide


potassium sodium zinc iron copper gold


ETest yourself

AnswersReactions of metals and metal compounds(continued)

11 a These sentences describe how you could make crystals of zinc sulphate, but someinstructions have been missed out. Fill in the missing instructions.

Add some zinc oxide to dilute sulphuric acid in a test tube.

Warm the mixture in a beaker of hot water.

Evaporate some of the water by boiling the solution.

Filter to get the crystals of zinc sulphate.

b Write a word equation for the reaction between zinc oxide and sulphuric acid.

12 The table below gives the names of some salts and substances that can react to formthese salts. Fill in the empty boxes to complete the table.

13 Complete these word equations.

aaluminium

+ →aluminium

+ wateroxide acid sulphate

blithium

+nitric


c calcium +hydrochloric

→calcium

+acid

dpotassium

+hydrochloric

→ + + watercarbonate acid dioxide chloride

carbon potassium

chloridehydrogen

nitrate

lithium

sulphuric

zinc oxide + sulphuric acid → zinc sulphate + water

Leave the solution to cool.

Filter the mixture to remove excess zinc oxide.


Salt Substances that react together to make the salt

sodium chloride hydrochloric acid sodium hydroxide

copper sulphate sulphuric acid copper oxide

magnesium nitrate nitric acid magnesium carbonate

potassium sulphate sulphuric acid potassium hydroxide


EEnd of unit test

GreenReactions of metals and metalcompounds

1 Which of the following changes are chemical reactions?

A When magnesium is heated, it changes from shiny silver to a white powder.

B When chocolate is heated, it goes liquid and then solid.

C When salt is added to water, a clear liquid is produced.

D When a marble chip is added to an acid, bubbles are produced. 2 marks

2 a When calcium carbonate is added to hydrochloric acid, carbon dioxide gas is produced.

How could you prove that the gas is carbon dioxide? 2 marks

b When zinc is added to sulphuric acid, hydrogen gas is produced.How could you prove that the gas is hydrogen? 2 marks

3 When dilute hydrochloric acid is added to copper carbonate, a salt is produced.

Copy and complete this word equation for the reaction. 2 marks

copper carbonate + hydrochloric acid → copper

+ + water

4 A piece of zinc is added to some dilute sulphuric acid in a test tube.A chemical reaction takes place.

a i Describe two observations that show a chemical reaction is taking place. 2 marks

ii Name the salt made in this reaction. 1 markiii Name the gas produced. 1 mark

b A piece of magnesium is added to some more dilute sulphuric acid in another test tube. The metal reacts with the acid.

Describe one way in which this reaction is similar to that of zincand dilute sulphuric acid. 1 mark

c Zinc oxide reacts with sulphuric acid as shown in the word equation below.


i Using this information, copy and complete the general equation below to show how metal oxides react with acids. 1 mark

metal oxide + acid → + waterii When iron oxide reacts with sulphuric acid, what else is

produced apart from water? 1 mark


D-F-EUTest.qxd 18-Jun-04 1:44 PM Page 9

EEnd of unit test

GreenReactions of metals and metal compounds(continued)

5 10 cm3 of a dilute solution of potassium hydroxide are placed in a beaker. Dilute nitric acid is then added a few drops at a time and the solution tested with Universal Indicator paper after each addition. When the alkali has been neutralised no more acid is added.

a To what colour does Universal Indicator change to showneutralisation has taken place? 1 mark

b Write a word equation for this neutralisation reaction. 2 marks

c How could crystals of the salt from this reaction be obtainedfrom the neutral solution? 2 marks

6 Jo reacted copper oxide with dilute sulphuric acid. The diagram shows her experiment.

a What evidence is there that a chemical change has taken place? 1 mark

b i How could Jo ensure that all the acid is used up in the experiment? 1 markii Jane said that Jo could also use Universal Indicator paper to

check that the acid was used up.

What colour did Jane predict the indicator would be to showthat all the acid was used up? 1 mark

c Jo wanted to get pure crystals of the product of her experiment.

What two practical steps would she have to take to get the purecrystals? Give the reason for each. 1 mark

i Step 1: Reason: 1 markii Step 2: Reason: 1 mark


before after

copper oxide

dilutesulphuric

acid


EEnd of unit test

RedReactions of metals and metalcompounds

1 A piece of zinc is added to some dilute sulphuric acid in a test tube.A chemical reaction takes place.

a i Describe two observations that show a chemical reaction is taking place. 2 marks

ii Name the salt made in this reaction. 1 mark

b A piece of magnesium is added to some more dilute sulphuric acid in another test tube. The metal reacts with the acid.

Describe one way in which this reaction is similar to that of zinc and dilute sulphuric acid. 1 mark

c Zinc oxide reacts with sulphuric acid as shown in the word equation below.


Using this information, copy and complete the general equation below to show how metal oxides react with acids. 2 marks

metal oxide + →→ + water

2 10 cm3 of a dilute solution of potassium hydroxide are placed in a beaker. Dilute nitric acid is then added a few drops at a time and the solution tested with Universal Indicator paper after each addition.When the alkali has been neutralised no more acid is added.

a What colour does Universal Indicator change to show neutralisation has taken place? 1 mark

b Write a word equation for this neutralisation reaction. 2 marks

3 Jo wants to make some copper sulphate. She reacts copper carbonate with dilute sulphuric acid to make the salt.

a Copy and complete this word equation for the reaction. 2 marks

copper carbonate + sulphuric acid →→ copper sulphate

+ +

b How could Jo make sure that all of the sulphuric acid is used up duringthe reaction to leave a clear, neutral solution? 2 marks

4 a The table on the next sheet shows some substances that are reacted together, and the products from these reactions. Write answers for A, B and C to complete this table. 3 marks



EEnd of unit test

RedReactions of metals and metal compounds(continued)

b Copy and complete this word equation:

tin + →→ tin nitrate + 2 marks

c Katie measured 50 cm3 of sulphuric acid and 10 g of copper oxide into two separatebeakers on a balance. She carefully mixed the copper oxide with the sulphuric acidand returned bothbeakers to thebalance. The liquidturned blue, but therewas no change of thebalance reading.

Why did the balance reading remain the same? 2 marks

5 Jo reacted copper oxide with dilute sulphuric acid. The diagram showsher experiment.

a Jo wanted to get pure crystals of the product of her experiment. What two practical steps would she have to take to get the pure crystals? Give the reason for each.

i Step 1: Reason: 1 markii Step 2: Reason: 1 mark

b Jo wanted her crystals to be as pure as possible. Suggest one precaution she should take to help achieve this. 1 mark

Jo says her conclusion is that when you react an oxide with an acid you always get a salt.

c i Does the evidence from her experiment support this conclusion? Give a reason. 1 mark

ii What should Jo do to test her conclusion? 1 mark


Substances reacted together Products of the reaction

tin nitric acid A hydrogen

lead oxide hydrochloric acid B water

C sulphuric acid calcium sulphate water

256.89 g 256.89 g

dilutesulphuric

acid

copperoxide

before after

copper oxide

dilutesulphuric

acid



EEnd of unit test

mark schemeReactions of metals and metalcompounds

Green (NC Tier 3–6)Question Answer Mark Level

1 A and D 1, 1 3

2 a Bubble the gas through limewater. 1 4The limewater goes milky or cloudy or forms a white precipitate. 1 4

b Hold a lighted splint to the mouth of a test tube of the gas. 1 4You will hear a squeaky pop when the gas ignites. 1 4

3 Copper carbonate + hydrochloric acid → copper chloride + carbon dioxide + water (L4 mark for chloride in correct space L5 mark for carbon 1 4dioxide in correct space.) 1 5

4 a i Bubbles are seen. 1 5Heat is given out. 1 5

ii Zinc sulphate. 1 6iii Hydrogen 1 5

b One from: 1 5Bubbles are seen.Heat is given out.Hydrogen is produced.A salt or a sulphate is produced.

c i Metal oxide + acid → salt + water (one mark for salt in correct space). 1 6ii Iron sulphate. 1 5

5 a Colour changes to yellow/green. 1 5

b Potassium hydroxide + nitric acid → potassium nitrate + water(one mark for each product). 2 6

c Evaporate (most of) the water. 1 5Leave the (saturated) solution to cool. 1 6

6 a Colour change/turned blue. 1 4

b i Add an excess of copper oxide. 1 5ii Green 1 5

c i Filter the liquid to remove surplus copper oxide. 1 6ii Heat the liquid to evaporate the water. 1 6

Scores in the range of: NC Level

4–6 3

7–11 4

12–16 5

17–25 6



EEnd of unit test

mark schemeReactions of metals and metalcompounds

Red (NC Tier 5–7*)Question Answer Mark Level

1 a i Bubbles are seen; heat is given out. 2 5ii Zinc sulphate. 1 6

b One from: 1 5Bubbles are seen; Heat is given out; Hydrogen is produced;A salt or a sulphate is produced.

c Metal oxide + acid → salt + water (one mark for acid in correct space,one mark for salt in correct space). 2 6

2 a Colour changes to yellow/green. 1 5

b Potassium hydroxide + nitric acid → potassium nitrate + water(one mark for each product). 2 6

3 a Copper carbonate + sulphuric acid → copper sulphate + water + carbon dioxide (one mark for water, one mark for carbon dioxide in any order as products). 2 6

b Add excess copper carbonate or add copper carbonate until someis left unreacted. 1 7Filter off the excess solid. 1 7Accept for two marks:Keep adding copper carbonate until the mixture is neutral whentested with Universal Indicator paper.

4 a A Tin nitrate. 1 6

B Lead chloride. 1 6

C Calcium hydroxide or calcium oxide. 1 7

b Nitric acid. 1 6Water 1 6

c Although a new compound has been made, there is no change in the total number of atoms. 2 7*or Mass is conserved. (2 marks)

5 a i Filter the liquid to remove surplus copper oxide. 1 6ii Heat the liquid to evaporate the water. 1 6

b Make sure the acid was made with distilled water/check the glassware is clean/cover the experiment to keep out dust. 1 6

c i No – she has only used one acid and one oxide. 1 7ii Repeat the experiment with different oxides and different acids. 1 7

Scores in the range of: NC Level

5–10 5

11–15 6

16–18 7

19–25 7*


E Pupil checklistReactions of metals and metal compounds


Learning outcomes I can do I can do I need to this very this quite do more well well work on this

I can describe some uses for some common metals.

I can describe the properties of metals.

I know what is produced when a base neutralises an acid.

I know how to name salts.

I know what is produced when an acid reacts with a metal.

I know what causes corrosion.

I can describe how to test for hydrogen.

I know what is produced when an acid reacts with a carbonate.

I can list the evidence that a chemical reaction has taken place.

I know what is produced when an acid reacts with a metal oxide.

I can suggest a suitable method for making a particular salt.

I can use preliminary trials to find out if a method of making a salt is practicable.

Pupil-Checklist.qxd 17-Jun-04 8:00 PM Page 5

E GlossaryReactions of metals and metal compounds


Word

alloy R

balanced equation R

cast iron R

conduct

salt

steel R

Definition

A hard, brittle alloy of iron and carbon that can be shaped by heating and pouring into moulds. R

A hard, strong alloy of iron and carbon that can be bentwithout breaking. R

To pass along or through. Thermal energy can be conducted.Electricity can be conducted.

A metal made of a mixture of metallic elements, or of a metal and a non-metal. R

A substance formed in a neutralisation reaction.

A chemical equation where the number of atoms on one sidebalances the number of atoms on the other side. R

Glossary.qxd 18-Jun-04 11:33 AM Page 6

E Key wordsReactions of metals and metal compounds

alloy R

balanced equation R

cast iron R

conduct

salt

steel R

alloy R

balanced equation R

cast iron R

conduct

salt

steel R

Sheet 1 of 1

Sheet 1 of 1


Key wordsE Reactions of metals and metal compounds


Keywords.qxd 18-Jun-04 11:35 AM Page 5


E Book answersReactions of metals and metal compounds

E1 What is a metal?Greena Metals are strong, some do not rust, they are

shiny, good conductors of electricity and heat,some are magnetic.

b Plastic does not conduct electricity, so the wirewill be safe to handle when covered with plastic.

c Plastic is a poor conductor of heat, so thehandles will not get hot.

d sodiume iron1 a Either copper or aluminium.

b Any one from: copper, iron, steel oraluminium.

c Any one from: iron, steel, cobalt or nickel.2 Individual answers.3 a There are numerous possible answers, all

non-metals. Any one from: wood, glass,paper, cloth, etc.

b Appropriate example from the materialchosen, e.g. saucepan handles from wood, etc.

4 Individual answers.

Reda Metals are strong, some do not rust, they are

shiny, good conductors of electricity and heat,some are magnetic.

b sodiumc irond Any three from: sodium, magnesium, mercury,

calcium, zinc.e Below –38 °C the mercury would freeze and

break the glass; above 350 °C it would boil andbreak the glass.

1 gold – jewelleryiron – magnetssteel – bridges and large buildingschromium – plating onto other metals toprevent rustingcopper – electric wiressilver – jewellerynichrome – for making heating elementsaluminium – cables between electricity pylonsbrass – prongs on electrical plugsmercury – thermometerssodium – making many chemical compoundsmagnesium – making many alloyscalcium – making many compounds and in soapmakingtin – plating steel used to make ‘tin’ canslead – roofing material and in car batterieszinc – plating metals to prevent rustingNichrome and brass are alloys.Other additional metals and uses may beaccepted if correct.

2 See below.

before5000 BC

Stone Agegold pieces

Egyptians usedgold, silver, copper

and bronze injewellery

Hittites madeiron from rocks

Chineseinventedcast iron

Dud Dudleymade cast iron

to be used in industry

Henry Bessemer madelarge amounts of cheap

steel for industry

3000 BC 1200 BC 1665 AD 1856

3 a Either mercury or nichrome (alloy). Mercuryis sometimes used in electrical switches, butmore commonly in thermometers. Nichromeis used in making the elements in heaters andtoasters.

b Mercury is a relatively poor conductor of heatcompared to most metals. Its most commonuse is in thermometers because it is a liquidat normal temperatures.

4 Individual answers.5 a mercury

b Individual answers based on the expansion ofa liquid on heating.

E2 Salt on the roadsGreena Neutralisation is the reaction of an acid with an

alkali to form a salt and water.b 7c The resulting solution will be either acid or

alkaline.d Potassium chloride.e Magnesium chloride.1 sodium hydroxide + hydrochloric acid →

sodium chloride + waterpotassium hydroxide + hydrochloric acid →potassium chloride + water

Book Answers.qxd 18-Jun-04 12:44 PM Page 12


E Book answersReactions of metals and metal compounds (continued)

2 a

b

3 Individual answers.4 Copper chloride.

Reda When the pH =7.b The volume of acid needed to neutralise the

alkali was one-tenth the volume of the alkali.1 sodium hydroxide + hydrochloric acid →

sodium chloride + waterpotassium hydroxide + hydrochloric acid →potassium chloride + water

2 Individual answers.3 a magnesium hydroxide + hydrochloric acid →

magnesium chloride + waterb zinc hydroxide + hydrochloric acid →

zinc chloride + waterc calcium hydroxide + sulphuric acid →

calcium sulphate + waterd sodium hydroxide + nitric acid →

sodium nitrate + water

tripod stand

salt solutionin evaporatingdish

Bunsenburner

heatingmat

Take a solution ofsodium hydroxide

Add a solution of hydrochloric acid of the same

concentration and volume

Mix well to producea neutral solution

Evaporate

Collect crystals of sodiumchloride salt

4 A pH sensor is more accurate because it providesan exact pH number as the neutralisationproceeds.

5 Water molecules are always composed of thesame atoms, two of hydrogen and one of oxygen.

6 a stearic acid + sodium hydroxide →sodium stearate + water

b Sulphuric acid.

E3 Acids attack metalsGreena The zinc is corroded and bubbles are given off;

or there is fizzing.b Calcium sulphate.c Hydrochloric acid.d tin1 a iron + sulphuric acid → iron sulphate +

hydrogenb magnesium + sulphuric acid → magnesium

sulphate + hydrogen2 Bubbles of hydrogen gas would be given off. The

nail would get smaller or disappear as it turnedinto iron chloride solution in water.

3 Put a lighted splint near the top of a test tubefull of a gas. You will hear a ‘pop’ if the gas ishydrogen.

Reda The zinc is corroded and bubbles are given off;

or there is fizzing.b Zinc nitrate.c i iron

ii Iron is more reactive than tin.iii tin

1 A salt and hydrogen gas.2 a magnesium + sulphuric acid → magnesium

sulphate + hydrogenb calcium + hydrochloric acid → calcium

chloride + hydrogenc iron + sulphuric acid → iron sulphate +

hydrogen3 The iron nail would react with the hydrochloric

acid. Iron chloride solution and hydrogen gaswould be formed.

4

water

hydrogen

sulphuricacidpieces

of zinc



E Book answersReactions of metals and metal compounds (continued)

5 Put a lighted splint near the top of a test tubefull of each of the gases. You will hear a ‘pop’ ifthe gas is hydrogen.

6 a Sodium and hydrochloric acid.b sodium + hydrochloric acid →

sodium chloride + hydrogen

E4 Acids attack carbonatesGreena Carbon dioxide.b A salt, water and carbon dioxide.c Copper sulphate.d copper carbonate + sulphuric acid → copper

sulphate + water + carbon dioxide1 a sodium carbonate + hydrochloric acid →

sodium chloride + water + carbon dioxideb Reactants are sodium carbonate and

hydrochloric acid. Products are sodiumchloride, water and carbon dioxide.

c Sodium chloride.2 a Put some copper carbonate in each of two test

tubes. Add some hydrochloric acid to one ofthe tubes and sulphuric acid to the other testtube. Appropriate drawing to show this.

b Bubbles are given off from the solution.3 copper carbonate + hydrochloric acid → copper

chloride + water + carbon dioxide

Reda Carbon dioxide.b The carbon and oxygen in carbon dioxide come

from the rearrangement of the carbon andoxygen atoms in the carbonate salt.

c The symbols of the compounds are the same inany language.

d i Copper sulphate.ii copper carbonate + sulphuric acid → copper

sulphate + water + carbon dioxideiii Copper carbonate reacts with sulphuric acid

to produce the blue salt copper carbonate,water and carbon dioxide gas. Heat is alsogiven off during the reaction.

1 The buildings contain carbonate minerals. Rainbecomes acid when it falls through the air anddissolves carbon dioxide. This acid rain reactswith the carbonates in the buildings.

2 Chemical symbols are the same in everylanguage.

3 a Put some copper carbonate in each of two testtubes. Add some hydrochloric acid to one ofthe tubes and sulphuric acid to the other testtube. Appropriate drawing to show this.

b Bubbles given off, heat given off or a colourchange.

4 ethanoic acid + calcium carbonate → calciumethanoate + water + carbon dioxide

5 Diagram as shown in text. The sodiumcarbonate solution reacts with the sulphuric acidwhen the pin breaks the bottle containing theacid. The carbon dioxide produced forces thewater from the extinguisher and the foamingsolution of carbon dioxide puts out the fire.

6 sodium carbonate + nitric acid →sodium nitrate + water + carbon dioxideThe reactants are sodium carbonate and nitricacid. The products are sodium nitrate, water andcarbon dioxide.

E5 Acids and metal oxidesGreena Rust is iron oxide. Rust removers are acid. The

acid reacts with the iron oxide and leaves aclean surface of iron.

b i filtrationii evaporation

c None of the products was a gas.d magnesium oxide + sulphuric acid →

magnesium sulphate + water1 a Magnesium oxide, sulphuric acid,

magnesium sulphate, water.b The reactants are magnesium oxide and

sulphuric acid. The products are magnesiumsulphate and water.

c Magnesium sulphate.magnesium oxide + sulphuric acid →magnesium sulphate + water

2 There is a colour change. Copper oxide is blackbut the copper sulphate solution is blue.

3 a Calcium oxide and sulphuric acid.b calcium oxide + sulphuric acid → calcium

sulphate + water

Reda i filtration

ii evaporationb The oxygen in the magnesium oxide joins the

hydrogen in the sulphuric acid to make water.c Hydrochloric acid, sulphuric acid, nitric acid,

nitric acid.1 There is a colour change. Copper oxide is black

but the copper sulphate solution is blue.2 a three

b The sulphur and the oxygen atoms.3 a Calcium oxide and sulphuric acid.

b calcium oxide + sulphuric acid →calcium sulphate + water

4 a Magnesium sulphate is a laxative. Ironsulphate is given to people suffering fromanaemia.

b Individual answers.5 iron oxide + hydrochloric acid → iron chloride +

water


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D-F-Unit Guides.qxd 16-Jun-04 3:08 PM Page 7 E Reactions ... 3/Unit E.pdfhave identified that there are chemical reactions between acids and metals and between acids and carbonates