GCSE Chemistry

Unit 2

Foundation Tier

[GCM21]WEDNESDAY 12 JUNE, MORNING

11830.02 MV18

Time1 hour 15 minutes, plus your additional time allowance.

Instructions to CandidatesWrite your Centre Number and Candidate Number in the spaces provided at the top of this page.You must answer the questions in the spaces provided. Do not write on blank pages. Complete in black ink only. Answer all six questions.

Information for CandidatesThe total mark for this paper is 80.Figures in brackets printed at the end of each question indicate the marks awarded to each question or part question.Quality of written communication will be assessed in Question 3(d)A Data Leafl et, which includes a Periodic Table of the Elements, is included in this question paper.

Centre Number

Candidate NumberGeneral Certifi cate of Secondary Education

2019

MV18

11830.02 MV18 2 [Turn over

1 Iron is extracted from its ore in the Blast Furnace. The extraction involves redox reactions.

(a) (i) Name the ore from which iron is extracted in the Blast Furnace. [1 mark]

(ii) Apart from iron ore, name one other substance added to the Blast Furnace. [1 mark]

(b) (i) Name the reducing agent in the Blast Furnace and write balanced symbol equations to show the formation of this compound. [6 marks]

Name

Equations

(ii) Balance the symbol equation below for the production of iron in the Blast Furnace. [1 mark]

Fe2O3 + CO Fe + CO2

11830.02 MV18 3 [Turn over

(iii) Explain, in terms of oxygen content, why the reaction in (b)(ii) is a redox reaction. [5 marks]

11830.02 MV18 4 [Turn over

2 Ammonia is manufactured in the Haber Process. An iron catalyst is used in this process to increase the rate of the reaction.

The balanced symbol equation for the reversible reaction in the Haber Process is:

N2(g) + 3H2(g) 2NH3(g)

(a) (i) Explain how a catalyst increases the rate of a chemical reaction. [2 marks]

(ii) State two conditions which can be altered to change the direction of a reversible reaction. [2 marks]

1.

2.

11830.02 MV18 5 [Turn over

(b) A dynamic equilibrium is achieved in the reactionbetween nitrogen and hydrogen in the Haber Process.

Complete the following table by placing a tick () in thecorrect column. [5 marks]

Statement True FalseDynamic equilibrium occurs in a closed system.Dynamic equilibrium occurs when the rates of the forward and reverse reactions are equal.Dynamic equilibrium occurs when the rate of the forward reaction is greater than the rate of the reverse reaction.At equilibrium the amount of reactants is always equal to the amount of products.At equilibrium the amounts of reactants and products remain constant.

11830.02 MV18 6 [Turn over

(c) In the Haber Process the forward reaction is exothermic.

N2(g) + 3H2(g) 2NH3(g)

(i) Explain, in terms of bonds, why this reaction is exothermic. [3 marks]

11830.02 MV18 7 [Turn over

(ii) The covalent bonds which are present in the reactants and products are shown below the equation. Use these bonds and the bond energies given in the table to calculate the energy change for the forward reaction. [4 marks]

N2 + 3H2 2NH3

N N + H H H H H H

H

HHN

H

HHN

Bond Bond Energy/kJN N 916H H 436N H 386

Energy change = kJ

(iii) Using your answer to (c)(ii) suggest a value for the energy change of the reverse reaction. [1 mark]

11830.02 MV18 8 [Turn over

3 Alkenes are hydrocarbons which may be produced by cracking.

(a) (i) State the meaning of the term hydrocarbon. [1 mark]

(ii) Write the general formula of the alkenes. [1 mark]

(b) Write a balanced symbol equation for the complete combustion of C4H8 forming carbon dioxide and water.

[3 marks]

(c) Propene may be produced from the cracking of the hydrocarbon C7H16. One other product is formed in

this reaction.

(i) Write a balanced symbol equation for the cracking of C7H16. [2 marks]

(ii) Name the other product formed in this reaction. [1 mark]

(iii) Suggest why high temperatures are required for cracking reactions. [1 mark]

11830.02 MV18 9 [Turn over

(d) Identify the functional group present in alkenes and describe a chemical test for this functional group.

Write a balanced symbol equation for the chemical reaction which occurs when ethene is tested in this way.

[6 marks]

In this question you will be assessed on your written communication skills including the use of specialist terms.

11830.02 MV18 10 [Turn over

4 Calcium nitrate and calcium chloride are compounds often used in commercial treatments for garden plants.

(a) Calcium nitrate may be formed from the reaction of nitricacid with calcium hydroxide solution. An experiment wascarried out during which nitric acid was slowly addedfrom a burette to 25.0 cm3 of calcium hydroxide solutionin a conical flask.

(i) An indicator was added to the conical flask to showwhen the reaction was complete. Name a suitableindicator which could have been used in thisexperiment. [1 mark]

(ii) Name a piece of apparatus which was used toaccurately measure 25.0 cm3 of calcium hydroxidesolution. [1 mark]

11830.02 MV18 11 [Turn over

(iii) The balanced symbol equation for the reaction is:

Ca(OH)2 + 2HNO3 Ca(NO3)2 + 2H2O

Calculate the atom economy when calcium nitrate is made using this reaction. [3 marks]

Show your working out.

Atom economy = %

11830.02 MV18 12 [Turn over

(b) Anhydrous calcium chloride is used in an experimentto investigate rusting as shown below. An iron nail isplaced in three different test tubes (1, 2, and 3) underdifferent conditions. The test tubes were left forone week.

(i) In which test tube(s) would rusting have occurredafter one week? [1 mark]

(ii) What is the purpose of the oil in test tube 2?[1 mark]

(iii) What is the purpose of the anhydrous calciumchloride in test tube 3? [1 mark]

11830.02 MV18 13 [Turn over

(iv) Describe the appearance of rust. [2 marks]

(v) What is the chemical name for rust? [1 mark]

(vi) State one method of preventing the formation of rust.[1 mark]

11830.02 MV18 14 [Turn over

5 Molten lead(II) bromide undergoes electrolysis.

(a) What is meant by the term electrolysis? [1 mark]

(b) The apparatus below is used to carry out the electrolysis of molten lead(II) bromide.

batterylamp

negative electrodepositive electrode

pipeclay triangle

tripod

heatheatproof mat

crucible containing molten lead(II) bromide

(i) Name the material used to make the electrodes in this electrolysis. [1 mark]

11830.02 MV18 15 [Turn over

(ii) State two reasons why this material is used to makethe electrodes. [2 marks]

1.

2.

(iii) Suggest why this electrolysis experiment needs tobe carried out in a fume cupboard. [1 mark]

(iv) What name is given to the positive electrode?[1 mark]

(c) Complete the table to give details of the electrolysis ofmolten lead(II) bromide. [4 marks]

Negative electrode Positive electrode

Observations at the electrode

silvery grey liquid formed

Name of electrolysis product

11830.02 MV18 16 [Turn over

6 Oxygen and nitrogen are the most abundant gases found in the atmosphere.

(a) (i) State the colour of oxygen gas. [1 mark]

(ii) State one use for oxygen gas. [1 mark]

(b) Oxygen gas reacts with both metals and non-metalsto form oxides. Complete the following table givinginformation about the reaction of oxygen gas with theelements magnesium and sulfur. [5 marks]

Magnesium Sulfur

Observations during reaction with oxygen white fl ame

Appearance of product after reaction with oxygen

colourless gas

Nature of oxide formed (acidic or basic)

11830.02 MV18 17

(c) (i) State the percentage composition of nitrogen gas in the atmosphere. [1 mark]

(ii) Explain why nitrogen gas is unreactive. [2 marks]

(iii) Apart from nitrogen and oxygen, name two other gases which are present in the atmosphere.

[2 marks]

1.

2.

This is the end of the question paper

Permission to reproduce all copyright material has been applied for.In some cases, efforts to contact copyright holders may have been unsuccessful and CCEAwill be happy to rectify any omissions of acknowledgement in future if notifi ed.

For Examiner’suse only

QuestionNumber Marks

123456

TotalMarks

Examiner Number

11830.02 MV18

Sources

Q4b . . . © Chief Examiner / CCEAQ5b . . . © Chief Examiner / CCEA

© CCEA 2017

SYMBOLS OF SELECTED IONS

SOLUBILITY IN COLD WATER OF COMMON SALTS, HYDROXIDES AND OXIDES

Negative ions

SolubleAll sodium, potassium and ammonium saltsAll nitratesMost chlorides, bromides and iodidesEXCEPT silver and lead chlorides, bromides and iodidesMost sulfates EXCEPT lead and barium sulfatesCalcium sulfate is slightly soluble

InsolubleMost carbonates EXCEPT sodium, potassium and ammonium carbonatesMost hydroxidesEXCEPT sodium, potassium and ammonium hydroxidesMost oxidesEXCEPT sodium, potassium and calcium oxides which react with water

Name Symbol

Ammonium

Chromium(III) Cr3+

Copper(II) Cu2+

Iron(II) Fe2+

Iron(III) Fe3+

Lead(II) Pb2+

Silver Ag+

Zinc Zn2+

Name SymbolButanoate C3H7COO-

CarbonateDichromateEthanoate CH3COO-

HydrogencarbonateHydroxide OH–

Methanoate HCOO–

Nitrate NOPropanoate C2H5COO–

SulfateSulfi te

NewSpe

cifi ca

tion

Positive ions

© CCEA 2017

For fi rst teaching from September 2017

Data Leafl etIncluding the Periodic Table of the Elements

For the use of candidates takingScience: Chemistry,

Science: Double Awardor Science: Single Award

Copies must be free from notes or additions of anykind. No other type of data booklet or information

sheet is authorised for use in the examinations

gcse examinations

chemistry

227

89

139

57

256

101

223

87

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88

261

104

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277

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271

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272

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140

58

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150

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11

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* 58 – 71 Lanthanum series† 90 – 103 Actinium series

a = relative atomic mass

x = atomic symbolb = atomic number

THE PERIODIC TABLE OF ELEMENTSGroup

a

bx

*

†

1

11 2 3 4 5 6 7

0

285

112Copernicium

(approx)