UNIT TWO: CHEMISTRY

Chemistry is the study of matter, its properties and its changes or transformations. Matter is anything that has mass and takes up space (volume). The chemistry unit is found from pages 135 – 253 in your textbook. Pages 142 – 150 and 184 - 187 in your textbook are a review of grade 9 material. This review will be covered in a

handout (9review).

An excellent chemistry resource is the text Fundamentals of Chemistry written by Brady and Holum. You are free to sign a textbook out for your enjoyment.

Classification of MatterMatter

pure substances mixtures

elements compounds heterogeneous mixtures

solutions

Elements are substances that are found on the periodic table and cannot be broken down into simpler substances (basically).Compounds are substances that are a combination of elements in a fixed proportion. O2, H2O, C6H12O6, C30H62

Solutions (homogeneous mixtures) are a mixture of two or more substances such that only one phase is visible. The mixing is homogeneous to a molecular level. salt water, vodka, apple juice, alloys

For liquid solutions a good tip is that if the mixture is clear (could be coloured) then it is a solution.

A heterogeneous mixture is a mixture of two or more substances where there is more than one phase visible. The mixing does not take place at a molecular level. Oil and water, sand and water, ice and water, pizza and milk are good examples of these mechanical mixtures.

The Periodic Table

The Periodic Table has gone through many forms to its present day arrangement. Today the only changes that are possible for the future are the addition of more elements.

There are various levels of organization in the Periodic Table of your textbook. Try and answer these questions to discern this organization.

How are gaseous, liquid and solid elements displayed?

How are metals, non-metals and metalloids displayed.

The highlight of the Periodic Table is the organization of elements in families or groups (vertical columns). These families have similar Lewis Dot diagrams and display similar chemical properties.

Properties of Matter

A physical property is a characteristic property of a substance. The substance does not change its identity. state of matter, hardness, odour, solubility, colour.

A chemical property is a characteristic behaviour that occurs when a substance changes to a new substance. The change itself is called a chemical change. (In a physical change the substance only changes state.)

PEN

location charge massproton nucleus +1 1 uelectron orbit -1 0 uneutron nucleus 0 1 u

an electron actually weight 1/1876 u but we treat this as 0 u for our purposes

The information about an element is conveyed with following notation.

bc

AZ X

X is the element symbol

A is the atomic mass in atomic mass units (u)

Z is the atomic number (number of protons)

b is the electric charge

c is the number of atoms

Remember these simple rules for analyzing elements.

#p+ + #e- = b

#p+ + #no = A

B115

-how many pen are there? (neutral!!)

Hydrogen deuterium tritium

-only hydrogen has names for its isotopes

Mg2412 Mg25

12Mg26

12

F199 Si28

14 U23892

H11 H21 H31

2126

C 33717

ClAu197

796 p+, 4e-, 6no 17 p+, 20e- , 20no 79 p+, 78e- , 118no

-try the PEN sheet -the # of p+ determines which element it is

Average Atomic Mass

Naturally occurring elements are made up of different isotopes. The mass of an element found on a periodic table is the average atomic mass. It can be calculated by a weighted average of the isotope masses and their percentage natural occurrence.

%7.78

2412Mg

%13.10

2512Mg

%17.11

2612Mg

uAverage

Average

32.24

)1117.0(26)1013.0(25)787.0(24

These calculations may not agree exactly with the average atomic mass on the periodic table because the isotope masses above are not exact. When making an atom from protons and neutrons mass is lost in the fusion or fission reaction.

Lewis Dot DiagramsIn some ways chemistry can be thought of as how atoms interact with other atoms. The outer shell electrons or valence electrons are the most important part of this interaction. Lewis Dot Diagrams show the valence electrons of an atom. The pattern of valence electrons is the fundamental pattern that determines chemical reactivity.

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

The fourth period is 18 elements wide however the patterns set up in the second and third rows continue for the rest of the periodic table. The transition metal electrons do enter the outer shell but drop down a level upon leaving the transition metal area. The loss of these ten electrons means that once again the inert gases need eight electrons in their outer shell. Lewis Dot Diagrams are not drawn for transition metal elements.

K Ca Ga Ge As Se Br Kr

Rb Sr In Sn Sb Te I Xe

Ions

An ion is an electrically charged atom or group of atoms. Atoms lose or gain electrons to have a full outer shell. They become isoelectronic with the nearest Noble gas. This full outer shell is a more stable arrangement than the neutral atom. Noble gases do not form ions because they are already quite stable with a full outer shell.

Every atom has two choices (full or empty) but the choice which involves gaining or losing the least electrons forms the preferred ion.

Hydrogen can lose or gain one electron to become stable (H+ or H-) however the positive hydrogen ion (p+ or H+) is much more common.

Carbon and all other members in its group can lose or gain four electrons to become stable, however since this involves so many electrons neither positive or negative ion is common.

F- Cl- Br- I- At-

Li+ Na+K+ Rb+ Cs+

Be+2 Mg+2 Ca+2 Sr+2 Ba+2

B+3 Al+3 Ga+3 In+3 Tl+3

O-2 S-2 Se-2 Te-2 Po-2

N-3 P-3 As-3 Sb-3 Bi-3

IONIC COMPOUNDSIonic compounds are made up of oppositely charged ions (from a metal and a non-metal). Ionic compounds are also known as salts. Ions are charged particles. An atom or group of atoms (polyatomic) can be an ion.

There is an inherent stability to a full octet of electrons. Noble gases have a full outer shell of eight electrons and are so stable they rarely form compounds.

Na F Na+ F-NaF

Sodium Fluoride

opposite charges attractpositive first negative second (ending with “ide”)formula unit (not a molecule!)

ALL COMPOUNDS ARE NEUTRAL!!

Mg Br Mg+2 Br-Br-

MgBr2 Magnesium Bromide

B+3 N-3

BN Boron Nitride

B N

Al O

Al2O3 Aluminum Oxide

Al+3 O-2O-2Al+3O-2

Crossing the charges over is an easy way to arrive at the formula unit. Remember to reduce to lowest terms.

Al+3 O-2

The goal is always to make a neutral compound.

You are expected to draw Lewis Dot Diagrams of ionic compounds as shown. Remember to show the electric charge on the ions. Most times you will be asked to write the formula unit and chemical name only.

The Periodic Table tells you the electric charge possible for every element although you shouldn’t need this help since the column location tells you the charge for an element.

State formula of the following compounds.

a) Potassium Sulfide b) Magnesium Iodide

c) Boron Hydride d) Beryllium Phosphide

State the name of the following compounds.

• AlF3 b) Na2O c) BaSe d) Cs3N

Draw Lewis Dot Diagrams for (a) of each question

answers

The goal of a proper nomenclature system is simplicity and clarity. These requirements mean that you must figure out the formula with a periodic table. This does not sacrifice clarity since there is only one possible compound between a metal and a non-metal. Transition metals (and a few regular metals) are complicated by the fact that some of them have more than one ion possibility. If a transition metal has more than one possible charge the chemical name contains a Roman Numeral to indicate the charge the transition metal possesses.

Remember that if a non-metal is negatively charged then it has only one possible charge.State the formula of each of the following compounds?

a) Silver Bromide b) Zinc Sulfide

State the name of the following compounds.

a) CdH2 b) Zn3N2

AgBr ZnS

Cadmium Hydride

Zinc Nitride

State the formula of each of the following compounds?

a)Iron (III) Iodide b) Manganese (VII) Oxide

c) Nickel (II) Phosphide d) Gold (I) Bromide

State the name of the following compounds.

a)PbO2 b) Pt3N2 c) Fe2O5d) Hg2Cl2

FeI3 Mn2O7 Ni3P2 AuBr

Lead (IV) Oxide Platinum (II) Nitride

Iron (V) Oxide Mercury (I) Chloride

Before the Stock system (Roman Numerals) a different system for nomenclature of multivalent metal elements was used. An “ous” suffix on the metal indicated a lower charge while an “ic” suffix indicated a higher charge. This system fell out of favour when some metals were found to have more than two possible charges. In addition if an element had a latin based symbol then the latin name of the element had to be used.This system will not be included on any test or quiz.State the formula of each of the following compounds?a) Cuprous Oxide b) Cupric Chloridec) Ferrous Nitride d) Ferric IodideFerrous Fe+2 Ferric Fe+3

e) Nicklelous Sulfide f) Nickelic CarbideState the name of the following compounds.a) AuN b) MnO2 c) SnCl4

CuO CuCl2 Fe3N2 FeI3 NiS Ni4C3Auric Nitride Manganic Oxide Stannic Chloride

Molecular Compounds

Ionic compounds form between ions. Positive ions can be metals or polyatomic ions while negative ions can be non-metals or polyatomic ions. Metals and non-metals form ions so they have a full outer shell of electrons. The ions are then bonded to each other because of opposite charges.

There is another way to have a full outer shell of electrons and it is accomplished by sharing electrons between two non-metals.

Covalent bonds hold atoms together because the two atoms are attracted to a pair of common electrons. This never ending tug of war means the two atoms are linked to each other. The whole situation is energetically stable because each atom senses that it has a full outer shell of electrons.

Covalent compounds are always made from non-metals.

H HH H

Lewis dot diagrams

C H C

H

H

H H

H2

CH4

each atom has access to a full outer shell of electrons

Don’t show rings on a test

Try making Lewis dot diagrams for the following molecular compounds.

H2O NH3 Cl2 C2H6 C2H6O BCl3

O

H

H N

H

H H Cl Cl

C C O HH

H

HH

HC C H

H

H

HH

H

B ClClCl

Every atom needs a full outer shell

Drawing Lewis dot diagrams becomes tiresome so we will now move to stick diagrams. Two dots that are involved in bonding are represented by a stick. Electrons that are not involved in bonding are not shown but remember they are present.

N

H

H H

bonding electrons

non-bonding electrons

N

H

H H

try SiH4, Br2, C2NH7, C3NOH9

Si

H

H

H

HBr Br

CC

H

N H

H

H H

H

H

NC

H

C H

H

H H

H

HNC

H

O C

H

H H

H

H

C

H

H

H

CC

H

C O

H

H H

H

H

N

H

H

H

Molecular compounds that have the same chemical

formula but a different structure are called isomers.

NCH

O CH

H HH

H

C

H

HH

CCH

C OH

H H

H

H

N

H

HH

C

C

H

C O

H

H

H

H

H

N

H

H

H

these are isomers

these are not

The nomenclature of molecular compounds can be very comp-licated but there is a simple system for molecular compounds that are made up of two kinds of elements. This system of nomenclature uses prefixes to denote the number of atoms in a molecule. The prefixes used are as follows.mono

ditri

tetrapentahexaheptaoctanonadeca

A few molecular compound’s names simply must be memorized. Examples of these include water, hydrogen peroxide and ammonia

CI4

N2O4

P4O10

Sulfur Hexafluoride

Phosphorous Pentachloride

Nitrogen Dioxide

SF6

PCl5

NO2

Carbon Tetraiodide

Dinitrogen Tetraoxide

Tetraphosphorous Decaoxide

STICK DRAWINGSNon-metal atoms which make up molecular compounds follow bonding patterns.Carbon, Silicon 4 bonds Nitrogen, Phosphorous 3 bonds Oxygen, Sulfur 2 bondsHydrogen, Fluorine, Chlorine 1 bond Bromine, IodineAtoms that can make only one bond are considered “chain enders”.

The compounds that will be made on the following pages will have mostly carbon and hydrogen. Carbon forms the backbone or skeleton of many covalent compounds because it can make 4 bonds which allows for infinite variety. The chemistry of carbon is called organic chemistry. Silicon has been proposed as an alternative “life” atom but it is not as suited energetically for the task as carbon.

Non-metal atoms can make up to 3 bonds at once to another atom since it is possible to overlap 3 single electrons at one time.

C HCH

In the plane of the screen

Behind the screen

In front of the screen

H-C C-H

Making a covalent compound means finding an arrangement so that each element has the proper number of sticks.

C4H11NO

H H

| | H H H H HrOrCrCrH | | | | / |HrCrCrCrNrOrCrH H HrCrH | | | | | | H H H H H HrNrCrH | |these are isomers H H

H H | | OrCrCrH H H | | | | | | H |HrCrCtCrNrOrCrH | | | | | | | HrNrCrCrH H H H H H / \ \ H H H

Look at what happens when two hydrogen atoms or other chain enders are removed from neighbouring atoms

H H | | H H OrCrCrH | | | | |HrCrCoCrNrOrCrH | H | | | | | | H H H HrNrCtCrH | H

Let’s remove another two hydrogen atoms from neighbouring atoms.

Stable chemicals will not have 3 membered rings (4 is difficult too).

When given a chemical formula to turn into a stick drawing follow these steps.

C3H5NO

H | HrOrCtCtNrCrH | | H H

1. Draw the skeleton (no chain enders).

2. Put in all possible hydrogens.

3. Remove hydrogens to make final compound.

OrCrC-N-C

H H H | | |HrOrCrCrNrCrH | | | | H H H H

The general formula for an organic com-pound with no double or triple bonds (or rings) is as follows.

CxNyOzH(2x+y+2) (this is not on the test)

Phosphorous counts as a nitrogen. Sulfur counts as an oxygen.All chain enders count as hydrogen.

Make two different stick drawings for each of the following chemical formulas.

C4H4O C6H6 C2H7NO2

C5H7N C3H2O2F2 C4H5SBr

Now build the molecules with the kits provided. See which bonds rotate and how the molecule can change shape.

CHEMICAL EQUATIONS

The world around us utilizes chemical reactions every day. Chemical reactions or chemical equations show how atoms or molecules change into a new arrangement of atoms or molecules.

A common example of a chemical equation is respiration.

glucose + oxygen ----> carbon dioxide + water word equation

(simple)C6H12O6(s) + O2(g) ----> CO2(g) + H2O(l)

skeleton equation

C6H12O6(s) + O2(g) ----> CO2(g) + H2O(l)

reactants products

reacts with

combines with

to produce

to make

to yieldsolid gas liquid

(aq) means aqueous (dissolved in water)

The Law of Conservation of Mass applies to all chemical reactions. It states that in a chemical reaction the total mass of the reactants is always equal to the total mass of the products.

Practically this means that matter is not created or destroyed. Chemical reactions change the arrangement of atoms not the number or type of atoms. This means that a proper chemical equation is balanced with regard to the number of atoms on either side of the chemical equation.

When balancing chemical equations there are four rules to follow.1. Only write numbers in front of the chemicals in a reaction. 2. Balance atoms other than oxygen or hydrogen.3. Balance oxygen or hydrogen.4. Check. If it is not balanced go back to step 2.

The first rule is important so that you do not change the type of molecules present. When applying the third rule it helps to balance the oxygen or hydrogen that is present in only one location on the reactant and product side.

C6H12O6(s) + O2(g) ----> 6CO2(g) + H2O(l)

C6H12O6(s) + O2(g) ----> 6CO2(g) + 6H2O(l)

C6H12O6(s) + 6O2(g) ----> 6CO2(g) + 6H2O(l)

One molecule of solid glucose reacts with six molecules of gaseous oxygen to produce six molecules of gaseous carbon dioxide and six molecules of water.

This is an example of a word equation (difficult).

N2 + H2 NH3

N2 + H2 2NH3

N2 + 3H2 2NH3

Mg(NO3)2 + Al2(SO4)3 MgSO4 + Al(NO3)3

3Mg(NO3)2 + Al2(SO4)3 MgSO4 + 2Al(NO3)3

3Mg(NO3)2 + Al2(SO4)3 3MgSO4 + 2Al(NO3)3

C6H14 + O2 CO2 + H2O

C6H14 + O2 6CO2 + H2O

C6H14 + O2 6CO2 + 7H2O

C6H14 + 9.5O2 6CO2 + 7H2OOnly whole numbers!!

2C6H14 + 19O2 12CO2 + 14H2O

Try balancing these reactions.

P + Cl2 PCl5C4H10 + O2 CO2 + H2O

(NH4)3PO4 + Ca(NO3)2 Ca3(PO4)2 + NH4NO3

2 + 5 22 +13 8+ 10

2 + 3 1+ 6

TYPES OF CHEMICAL REACTIONSChemical reactions can be broken down into five types.

Synthesis reactions occur when two types of matter combine to form one type of matter.

A + B AB 8Fe + S8 8FeS

Decomposition reactions occur when one type of matter breaks down into two or more types of matter.

AB A + B 2H2O 2H2 + O2

Single Displacement reactions occur when an element is displaced from a compound by another element.

A + BC B + AC Mg + 2AgCl 2Ag + MgCl2

Double Displacement reactions occur when ions or elements are exchanged between compounds.

AB + CD AD + CB

Ca(NO3)2 + Na2(CO3)2 CaCO3 + 2NaNO3

Combustion reactions occur when elements or compounds react with oxygen to form oxides.

2Ba + O2 2BaO CH4 + 2O2 CO2 + 2H2O

POLYATOMIC IONSPolyatomic ions are charged groups of atoms that tend to stay together. Ammonium sulfate (NH4)2SO4 is an ionic molecule that is made up of 2 ammonium ions (NH4

+) and a sulfate ion (SO4-2).

Evidence for ions in a compound is found in a conductivity test. Conductivity of an aqueous solution of the test substance generally confirms the presence of ions in a substance. Polyatomic ions are made up of non-metals that are covalently bonded. demo conductivity

When dealing with polyatomic ions treat them as a complicated element (something that cannot be broken down), that you have been given the formula and charge of.

Naming molecules with polyatomic ions is similar to naming simple ionic compounds. First comes the positive ion next comes the negative ion. There is no change to the ending of a negative polyatomic ion.

NH4+ OH- NH4OHAmmonium hydroxide

Barium nitrate

Calcium phosphate

Nickel (III) permanganateIron (VI) carbonate

Ba+2 NO3- Ba(NO3)2

Ca+2 PO4-3 Ca3(PO4)2

Ni+3 MnO4- Ni(MnO4)3

Fe+6 CO3-2 Fe(CO3)3

(NH4)2S

Al(ClO3)3

Cu3PO4

Zn(OH)2

Au2(SO4)3

Ammonium sulfide

Aluminum chlorate

Copper (I) phosphate

Zinc hydroxide

Gold (III) sulfate

Show the covalent bonding structure of these polyatomic ions.

Iron (II) Nitrate

Aluminum Phosphate

Zinc Chlorate

Ammonium Carbonate

LiOH

Mn(CN)7

Ag2CO3

Pt(CrO4)2

Fe(NO3)2

AlPO4

Zn(ClO3)2

(NH4)2CO3

Lithium Hydroxide

Manganese (VII) Cyanide

Silver Carbonate

Platinum (IV) Chromate

FACTORS THAT AFFECT RATES OF REACTION

The rate of a chemical reaction is defined as the amount of product formed per unit time. It also can be thought of as the amount of reactant used up per unit time.

Chemical reactions occur with a variety of rates. Gasoline is burned quickly in a running car while rusting of a car takes place very slowly. (think of more examples of fast and slow reactions)

Kinetic Molecular Theory: A Collision Model

Atoms and molecules are in a constant state of motion and collide with each other. Chemical reactions occur when reactants collide with enough energy and proper orientation to cause the chemical change to occur. The chemical change occurs when the chemical bonds of the reactants break and the chemical bonds of the products form. According to this collision model then, there are two ways to increase the rate of reaction.

•Increase the number of collisions.

•Increase the fraction of collisions that are effective.

The collision model helps us to understand how temperature, concentration, surface area and catalysts affect the rate of reaction.

Temperature

Temperature (average kinetic energy) is an indication of how fast particles are moving.

Increasing temperature increases the number of collisions per unit time which increases the rate of reaction. An increase in temperature also increases the fraction of collisions leading to products because more collisions have the necessary energy to react. An increase of 5o -10o often doubles the rate of reaction. cold blooded, winter, freezers

Concentration

Concentration (particles per unit volume) affects the number of collisions between particles. Increased concentration increases the number of collisions which increases the rate of reaction.

Surface Area

Reactions occur where reactants meet and collide. Increasing surface area increases the rate of reaction by increasing the number of collisions between reactants. (powder, lycopodium)Catalysts

A catalyst is a substance that increases the rate of a chemical reaction without being consumed by the reaction. Catalysts work for a variety of reasons. They can bring together the reactants in such a way to ensure perfect orientation or they might lower the energy needed for a reaction to occur. Research of catalysts is important because speeding up reactions saves time or allows a reaction to be utilized for the first time.

CHAPTER EIGHT: ACIDS AND BASES

Properties of Acids and Bases

Acids are sour-tasting, water-soluble substances that conduct electricity when dissolved in water. They react with many metals to form hydrogen gas.

The most important property of acids is that they all produce hydrogen ions (H+) when dissolved in water.

Bases are bitter-tasting water-soluble substances that feel slippery and are good conductors of electricity when in aqueous solution.

The most important quality of bases is that they produce hydroxide ions (OH-) when dissolved in water.

Bases can also be described as alkaline eg. batteries.

Acids and bases are both corrosive but only bases are caustic. tin can demo

Acids and bases are very important substances in our society (tables on pages 293 and 294). Acidsvinegar (acetic acid) HC2H3O2(aq) salad dressingcitric acid HC6H7O7 (aq) citrus fruitascorbic acid HC6H7O6 (aq) vitamin Clactic acid HC3H5O3 (aq) sour milkcarbonic acid H2CO3 (aq) carbonated drinksacetylsalicylic acid HC9H7O4 (aq) aspirinsulfuric acid H2SO4 (aq) battery acid

Basessodium hydroxide NaOH(aq) drain cleanerpotassium hydroxide KOH(aq) soap, cosmeticsaluminum hydroxide Al(OH)3(aq) antacidsammonium hydroxide NH4OH(aq) windexsodium bicarbonate NaHCO3(aq) baking sodapotassium sulfite K2SO3(aq) food preservative

Read pages 322-323 and answer questions a-h, 1-4. This would form the basis of a good extended response question on a test.

Important acids to memorize include,

Hydrochloric acid, HCl(aq), hydrobromic acid, HBr(aq), Hydroiodic acid, HI(aq).

More complicated acids to memorize include,

Nitric acid, HNO3(aq), Chloric acid, HClO3(aq), Acetic acid HC2H3O2(aq), Carbonic acid, H2CO3(aq), Sulfuric acid, H2SO4(aq), and Phosphoric acid, H3PO4(aq).

When these acids dissolve in water they lose H+ ions and form “ate” ions.

You are not responsible for memorizing the acids on this page. Many acids can be derived from the acids of the previous page.

perchloric acid HClO4 perchlorate ion

chloric acid HClO3 chlorate ion

chlorous acid HClO2 chlorite ion

hypochlorous acid HClO hypochlorite ion

Try H2SO3, HNO, HNO2, HBrO4 and name the accompanying ion as well.

Simple bases include,

Sodium hydroxide (NaOH), Potassium hydroxide (KOH), Magnesium hydroxide (Mg(OH)2) and Barium hydroxide (Ba(OH)2).

Other bases such as ammonia (NH3) react with water to produce hydroxide ions.

Some substances such as bicarbonate ion (HCO3

-) are amphoteric and behave as both an acid and a base.

The pH Scale

The strength of an acid or base solution is determined by the pH (p is short for portenz, a Danish word for strength) of a solution.

0 (acidic) 7 (neutral) 14 (basic)

The scale really is from -1.7 to 15.7

The scale is logarithmic or based on factors of 10. One unit on this scale corresponds to 10X or 1/10 X. look at picture (scan!) on p296, show log formula of pH then do exercise then read 298

]log[ HpH [H+] is hydrogen ion concentration (mol/L)

A: pH 3 B: pH 4Solution A is 1 unit more acidic than B.Solution A is 10 times as acidic as B.Solution A is 1 unit less basic than B.Solution A is 1/10 times as basic as B.

Solution B is 1 unit less acidic than A.Solution B is 1/10 times as acidic as A.

Solution B is 10 times as basic as A.Solution B is 1 unit more basic than A.

2 units on the pH scale corresponds to 100 times or 1/100. 3 units on the pH scale corresponds to 1000 times or 1/1000 times.

C: pH 9 D: pH 7 (acidity)

E: pH 11 F: pH 14 (basicity)

G: pH 8 H: pH 2 (acidity)

Write out 4 statements about acidity or basicity of the above solutions.

Read about the pH of different substances on p.298.

ELEMENTS AND OXIDES

Many acids and bases can be made from simple chemical reactions involving oxygen and water. Acids are made from non-metals and bases are made from metals.

metal + oxygen metal oxide (solid)

metal oxide + water metal hydroxide (solid)

If the metal hydroxide dissolves in water (aqueous) then it will act as a base. Not all metal hydroxides will dissolve in water.

2Mg(s) + O2(g) 2MgO(s)

MgO(s) + H2O(l) Mg(OH)2(aq)

Try the reactions for potassium.

4K(s) + O2(g) 2K2O(s)

K2O(s) + H2O(l) 2KOH(aq)

To make acids . . .

non-metal + oxygen non-metal oxide (l or g)

non-metal oxide + water acid (l or g) (aq)

The formula of a non-metal oxide or acid can be difficult to ascertain.

C(s) + O2(g) CO2(g)

CO2(g) + H2O(l) H2CO3(aq)

Try the reactions to form sulfur trioxide and sulfuric acid, diphosphorous trioxide and phosphorous acid and finally diphosphorous pentaoxide and phosphoric acid.

S(s) + O2(g) SO3(g)

SO3(g) + H2O(l) H2SO4(aq)

4P(s) + 3O2(g) 2P2O3(g)

P2O3(g) + 3H2O(l) 2H3PO3(aq)

4P(s) + 5O2(g) 2P2O5(g)

P2O5(g) + 3H2O(l) 2H3PO4(aq)

ACID BASE NEUTRALIZATION

ACID + BASE WATER + SALT

HCl(aq) + NaOH(aq) H2O(l) + NaCl(s)

2H3PO4(aq)+ 3Mg(OH)2(aq) 6H2O(l) + Mg3(PO4)2(aq)

Read p. 317-319 for more examples and uses of acid reactions (good communication extended response question).

Chemistry Safety

Safety is a very important concern in chemistry because of the inherent danger in dealing with reactive chemicals. This danger is increasing in our society because of the new chemicals being synthesized (plastics, cosmetics, cleaners, pharmaceuticals) and our increasing dependence on synthetic materials. This danger is also increasing because we process harmful “natural” materials (mining, combustion, by-products) at an ever increasing rate.

Read page 511.

WHMIS – Workplace Hazardous Materials Information SystemHHPS – Hazardous Household Product Symbols

Review the dangerous chemicals in the household and the precautions we all should take with the chemicals.