Chapter 2 Checklist
You should remember all these concepts and ideas from Science 10. Have you mastered
the concepts, applications, and skills associated with the following items? Check them off
when you are confident in your understanding.
Make sure you review this sheet prior to the Review Unit Exam.
Knowledge
use kinetic molecular theory and
collision theory to explain how
chemical reactions occur (2.2)
Key Terms
2.1
perspective
scientific
write balanced chemical equations
(2.2, 2.3)
technological
ecological
interpret balanced chemical equations
in terms of chemical amount (in
moles) (2.3)
convert between chemical amount
and mass (2.4)
economic
political
2.2
nuclear change
predict the solubility of elements and
ionic and molecular compounds in
water (2.6)
kinetic molecular theory
diagnostic test
predict products for chemical
reactions (2.5, 2.6)
state the technological application of
important chemicals and chemical
reactions (2.1, 2.3, 2.4, 2.5, 2.6)
identify risks and benefits of some
important chemical reactions (2.1,
2.3, 2.5)
balanced chemical equation
coefficient
2.3
create and critique experimental
designs (2.6)
chemical amount
Avogadro’s number
mole
2.4
molar mass
2.5
formation reaction
simple decomposition
reaction
complete combustion
reaction
Skills
read and write laboratory reports (2.6)
physical change
chemical change
classify chemical reactions (2.5, 2.6)
STS
STS
2.6
solution
solute
solvent
solubility
precipitate
single replacement reaction
double replacement reaction
precipitation
neutralization
Chemistry 20 – Review Unit
Writing Simple Composition and Simple Decomposition Reactions
A. Identify the reaction type by writing sc or sd in the margin to the left.
B. Provide the correct chemical formulas for reactants and/or products where necessary.
C. Where necessary, supply subscripts to indicate the phase (at room temperature unless otherwise
stated).
Simple Composition Reactions:
element
e.g. 2 Mg(s)
Simple Decomposition Reactions:
e.g.
+
+
element
O2(g)
compound
8 HgS(s)




compound
2 MgO(s)
element
8 Hg(l)
+
+
element
S8(s)
Notes:
1.
2.
Simple composition and decomposition reactions generally involve only pure substances.
Remember when predicting products to write the correct chemical formulas first and
then balance the equation.
1.
The first step in the production to sulfuric acid is to burn sulfur.
_____ S8(S) + _____ O2(g)
2.
In 1774 Joseph Priestly discovered oxygen by decomposing the calx (historical name for oxide) of
mercury.

_____ HgO(s)
3.
 _____ Na(l) + _____ Cl2(g)
Nitrogen from the air reacts with hydrogen to produce ammonia for fertilizers.
_____ N2(g)
5.
+ _____ H2(g)
+ _____ O2(g)

_____ H2O(g)
Copper ore is decomposed to remove the copper metal.
_____ CuO(s)
7.
 _____ NH3(g)
Rocket fuel burns to propel a satellite into space.
_____ H2(g)
6.
_____ Hg(l) + O2(g)
Molten table salt is industrially decomposed to produce molten sodium.
_____ NaCl(l)
4.
 _____ SO2(g)

Barbecue charcoal undergoes incomplete combustion to produce carbon monoxide.
_____ C(s)
+ _____ O2(g)

8.
Freshly cut lithium reacts with nitrogen from the air.
9.
A silver spoon or coin tarnishes when exposed to sulfur.
10. Molten lye is decomposed industrially into its elements.
_____ NaOH(l)
Chemistry 20 – Unit 5

Page 2
Chemistry 20 – Review Unit
Single and Double Replacement Reactions
A. Follow the previous instructions concerning identification of reaction type, writing correct chemical
formulas, indicating the state of matter and balancing the chemical equation.
B. Polyatomic ions are assumed to remain intact and are balanced as complete units.
C. It is convenient for balancing to write water as HOH for single and double replacement reactions.
Single Replacement Reactions:
element
e.g. Cl2(aq)
+
+
compound
2 NaI(aq)
Double Replacement Reaction:
compound
+
compound
e.g. Pb(NO3)2(aq) + 2 KI(aq)




element
I2(aq)
+
+
compound
2 NaCl(aq)
compound +
compound
PbI2(s) + 2 KNO3(aq)
Note:
Use the solubility table on Side 2 of the Alchem Periodic Table to predict the solubility of the products of
single and double replacement reactions in water.
1.
Sodium metal reacts vigorously with water.
_____ Na(s)
2.
+
+ _____ H2SO4(aq)
+
Al2O3(s)
 _____ Mg(OH)2(s) + _____ Ca(HCO3)2(aq)
 _____ Al (s)
+ _____ KCl(s)
Silver is recovered from silver ore by converting the ore into silver sulfate, which is then reacted with
copper.

+ _____ Ag2SO4(aq)
Phosphoric acid is produced at a fertilizer plant.
+ _____ Ca3(PO4)2(s)

Bromine is commercially produced from MgBr2 found in seawater.
_____ Cl2(g)
9.
_____ Fe(l)
+ _____ Mg(HCO3)2(aq)
+ _____ AlCl3(s)
_____ H2SO4(aq)
8.
_____ HCl(g) + _____ Na2SO4(aq)
Aluminum was first produced in 1825 by Hans Oersted using the following reaction:
_____ Cu(s)
7.

Slaked lime precipitates magnesium ions from hard water.
_____ K(s)
6.

+ _____ Fe2O3(s)
_____ Ca(OH)2(aq)
5.
_____ H2(g) + _____ NaOH(aq)
Molten iron is produced in the highly exothermic Thermit reaction.
_____ Al(s)
4.

Hydrogen chloride gas is produced in the laboratory from table salt.
_____ NaCl(s)
3.
_____ HOH(l)
+

_____ MgBr2(aq)
Hydrogen sulfide (sour) gas from a wild natural gas well reacts with the lead (II) chromate pigment in
paint on homes.
_____ H2S(g)
+
_____ PbCrO4(s)

10. Hydrogen sulfide gas from a wild sour (due to acidic compounds) natural gas well reacts with the
silver in cutlery and ornaments at home.
_____ H2S(g)
Chemistry 20 – Unit 5
+ _____ Ag(s)

Page 3
Chemistry 20 – Review Unit
Hydrocarbon Combustion and Other Reactions
A. Follow previous instructions concerning identification of reaction type, writing the correct formulas,
indicating the state of matter and balancing the chemical reaction.
B. Except for methane, the formula and phase of the hydrocarbons will be provided in all questions.
C. For other types of reactions the total equation will be given; products cannot always be predicted
easily.
hydrocarbon + oxygen  carbon dioxide + water vapour
7
e.g. C2H6(g) +
O2(g)  2 CO2(g) +
3 H2O(g)
2
Multiply by 2 to get the simplest whole number ratio:
Hydrocarbon Combustion Reactions:
 4 CO2(g)
e.g. 2 C2H6(g) + 7 O2(g)
+
6 H2O(g)
Notes:
1. Write water as H2O(g) in equations for hydrocarbon combustion reactions. When written as H 2O, balancing is easier.
Because of the heat produced in hydrocarbon combustion reactions, water is produced as a gas, H 2O(g) .
2. Balance C and H atoms first, O atoms last.
1.
A Bunsen burner, gas furnace and gas hot-water tank all burn natural gas.
_____ CH4(g)
2.
+
_____ H2O(g)

_____ O2(g)

_____ KCl(s)
+
_____ O2(g)
Limestone, mined in Kansas, is decomposed by heating to produce lime.

_____ CaCO3(s)
5.
+
Oxygen gas may be produced in the laboratory by heating potassium chlorate.
_____ KClO3(s)
4.
_____ CO2(g)
Propane is used as a fuel for trailers and where natural gas is not available.
_____ C3H8(g)
3.

+ _____ O2(g)
_____ CaO(s)
+
_____ CO2(g)
Gasoline is mixed with air in the carburetor and then exploded by a spark in the cylinder of a car
motor.
_____ C8H18(l)
6.
+
_____ O2(g)
A rock may be tested for limestone content by adding muriatic acid.
_____ CaCO3(s) + _____ HCl(aq)
7.

 _____ CaCl2(aq) +
_____ H2O(l)
+
_____ CO2(g)
A candle (assume C25H52) is burned for emergency or dining light.
Glass is prepared by heating sand with limestone and washing soda:
8.
_____ SiO2(s)
+
_____ CaCO3(s)
 _____ CaSiO3(s)
+
_____ CO2(g)
9.
_____ SiO2(s)
+
_____ Na2CO3(s)
 _____ Na2SiO3(s) +
_____ CO2(g)
10. Kerosene (assume C14H30) is a mixture of hydrocarbons and is burned as a fuel for stoves and lanterns
and for diesel and jet engines.
Chemistry 20 – Unit 5
Page 4
Chemistry 20 – Review Unit
Classifying Reactions and Balancing Chemical Equations
Classify each of the following reactions by writing sc, sd, sr, dr, hc, or o to the left of the equation.
Balance the equations using the simplest whole numbers possible.
_____ 1. ____Cu(s) + ____ O2(g)
 _____ CuO(s)
 _____ H2(g) + ____ O2(g)
_____ 3. ____ Fe(s) + ____H2O(g)  ____H2(g) + ____Fe3O4(s)
_____ 4. ____ AsCl3(aq) + _____ H2S(aq)  ____As2S3(s) + _____ HCl(aq)
_____ 2. ____ H2O(l)
 _____ CuSO4(s) + _____ H2O(g)
_____ 6. ____ Fe2O3(s) + _____ H2(g)  _____ Fe(s) + _____ H2O(l)
_____ 7. ____ CaCO3(s)  _____ CaO(s) + _____ CO2(g)
_____ 8. ____ Fe(s) + _____ S8(s)  _____ FeS(s)
_____ 9. ____ H2S(aq) + _____ KOH(aq)  _____ HOH(l) + _____ K2S(aq)
_____ 10.____ NaCl(l)  _____ Na(l) + _____ Cl2(g)
_____ 11.____ Al(s) + _____ H2SO4(aq)  _____ H2(g) + _____Al2(SO4)3(aq)
_____ 12.____ H3PO4(aq) + _____ NH4OH(aq)  _____ HOH(l) + _____ (NH4)3PO4(aq)
_____ 13.____ C3H8(g) + _____ O2(g)  _____ CO2(g) + _____ H2O(g)
_____ 14.____ Al(s) + _____ O2(g)  _____ Al2O3(s)
_____ 15.____ CH4(g) + _____ O2(g)  _____ CO2(g) + H2O(g)
_____ 5. ____ CuSO4  5H2O(s)
For the following problems, classify the reaction and then complete the balanced equation and the word
equation.
16. Reaction type:_____________________________________________________________________
Balanced equation: _____________ + ______________
Word equation:
sodium
+
chlorine
 _______________________
 sodium chloride
17. Reaction type: _____________________________________________________________________
 _____ CuS(s) + _____ KBr(aq)
Word equation: ______________ + _____________  __________ + ____________
Balanced equation: _____ K2S(aq) + _____ CuBr2(aq)
18. Reaction type: ______________________________________________________________________
Balanced equation: ________________ + _______________
Word equation:
Chemistry 20 – Unit 5
methane
+
oxygen
 _____ CO2(g) + _____ H2O(g)
 __________ + ___________
Page 5
19. Reaction type: ______________________________________________________________________
Balanced equation: ___ Zn(s)
Word equation:
+
___________ +
___ Pb(CH3COO)2(aq)  ___ __________ + ___ __________
_____________

lead
+ zinc acetate
20. Reaction type: ______________________________________________________________________
Balanced equation: ______________  _________________ + ____ H2(g)
Word equation:
ammonia  nitrogen + ________________
21. Reaction type: ______________________________________________________________________
Balanced equation: ______________  _________________ + ____ H2SO4(g)
Word equation:
sulfur trioxide +
water

_________________________
22. Reaction type: ______________________________________________________________________
Balanced equation: ___ Ca(NO3)2(aq) + ___ Na3PO4(aq)  ______________ + _______________
Word equation:
Chemistry 20 – Unit 5
_____________ + _______________

_____________ + ________________
Page 6
Chemistry 20 – Review Unit
Writing Balanced Equations
When writing the balanced equation for the following questions, be sure to include states of matter of all
reactants and products.
Note: Remember to read the balanced equation in terms of moles.
1.
Iron pipes are strongly attacked and corroded by hydrosulfuric acid. This problem is very serious for
“sour” natural gas wells – wells that contain sulfur compounds as well as methane. (iron (II) sulfide is
one product.)
Reaction type:
Balanced equation:
Word equation:
2.
Iron rusts in moist air to cause millions of dollars in damage each year.
Reaction type:
Balanced equation:
Word equation:
3.
iron + water + oxygen
 iron (III) oxide trihydrate (or iron (III) hydroxide)
Coal (assume C9H6) undergoes complete combustion.
Reaction type:
Balanced equation:
Word equation:
4.
The first recorded observation of hydrogen gas was made by Paracelsus (1493 - 1541) when he added
iron to sulfuric acid. (An iron (II) compound is one substance formed.)
Reaction type:
Balanced equation:
Word equation:
5.
In 1783, hydrogen and oxygen were first reacted by Henry Cavendish to produce water, and in 1937,
the Hindenberg, a hydrogen-filled dirigible, exploded by the same reaction.
Reaction type:
Balanced equation:
Word equation:
6.
Magnesium will continue to burn when lowered into a flask of carbon dioxide.
Reaction type:
Balanced equation:
Word equation: magnesium + carbon dioxide
Chemistry 20 – Unit 5

Page 7
7.
In the iron-exchange method of water softening, sodium zeolite (Na2Ze, where Ze represents a very
complex ion) removes calcium ions from hard water by precipitation. (Sodium zeolite, unlike most
sodium compounds, is not soluble in water.)
Reaction type:
Balanced equation: _____ Na2Ze(s) + _____ CaSO4(aq)

Word equation:
8.
The sodium zeolite may be regenerated by reversing a brine (NaCl) solution through the water softener.
Reaction type:
Balanced equation:
Word equation: calcium zeolite + sodium chloride
9.

Temporary hard water may be softened by heating.
Reaction type:
Balanced equation: __ NaHCO3(aq)
 __ Na2CO3(aq) + __ CO2(g) + __ H2O(l)
Word equation:
10. Soap may react with hard water to precipitate a bathtub-ring.
Reaction type:
Balanced equation: _____ NaC17H35COO(aq) + _____________
Word equation: ________________ + magnesium sulfate (aq)


11. Bottles of Sani-Flush carry a warning that dangerous fumes are produced by using Sani-Flush
(NaHSO4) together with chlorine bleach.
Reaction type:
Balanced equation: _ NaHSO4(aq) + _ NaClO(aq) + _ NaCl(aq)
 _ Cl2(g) + _ H2O(l) + _ Na2SO4(aq)
Word equation:
12. Joseph Priestly (1733 – 1804), in one of his many experiments with mercury, decomposed cinnabar
(mercury (II) sulfide).
Reaction type:
Balanced equation:
Word equation:
In 1784, Nicolas Leblanc discovered a new, economical preparation for soda ash (Na 2CO3) and caustic
soda (NaOH). (Questions 13 to 15.)
13. First, Leblanc reacted rock salt (NaCl(s)) with oil of vitriol ( H2SO4(aq)).
Reaction type:
Balanced equation:
Word equation:
Chemistry 20 – Unit 5
Page 8
14. Second, he reacted the sodium sulfate(s) from Equation 13 with charcoal and limestone.
Reaction type:
 __ Na2CO3(s) + __ CaS(s) + __ CO2(g)
Word equation: _________________ + carbon + calcium carbonate 
Balanced equation:
________ + ________ + ________
15. And last, Leblanc dissolved some of the soda ash from Equation 14 and reacted it with slaked lime (Ca(OH) 2(s)).
Reaction type:
Balanced equation:
Word equation:
16. In 1807, Humphry Davy jumped around in wild excitement when he discovered potassium by
electrically decomposing molten potash (potassium chloride).
Reaction type:
Balanced equation:
Word equation:
17. A boric acid solution is used in laboratory eyewashes to neutralize an ammonium hydroxide solution,
splashes into a student’s or technician’s eyes.
Reaction type:
Balanced equation:
Word equation:
Chemistry 20 – Unit 5
Page 9
Chemistry 20 – Review Unit
Significant Digits Worksheet
1.
2.
State the number of significant digits in each of the following:
a) 12.5
_______
d) 1.0 x 104
_______
b) 0.130
_______
e) 0.00001
_______
c) 0.00101
_______
Calculate the following each of the following using the correct number of significant digits.
a)
23 x 46 =
d)
34

25
e)
75 
b) 0.765 x 1.3 =
c)
34.756 x 2.09 =
3.
Calculate each of the following:
a)
b)
14.0
3.89
1433.98
4.
14
=
3
c)
34655.9
- 45.76
34.05 cm
2.39 dm
133.18 m
Note: Convert to the
largest unit
first.
Calculate each of the following:
a)
95.0 in 
2.54 cm

1 in
b)
125.9 ft 
1 yd

3 ft
c)
100 lb 
1 kgf

2.2 lb
Chemistry 20 – Unit 5
Page 10
Chemistry 20– Review Unit
The Mole Worksheet
1.
The mole is defined as _________________________________________________________________.
2.
Calculate the number of hydrogen molecules there are in 5.00 mol.
3.
Given that there are 100 g of calcium carbonate,
a)
calculate the number of moles that exist.
b) calculate the number of each atom that there is.
4.
If there are 4.25 x 1021 molecules of water, calculate the number of moles that exist.
5.
If there are 5.55 x 1022 atoms of zinc what is the mass?
6.
If there are 7.44 x 1022 molecules of ammonia what is the mass?
Chemistry 20 – Review Unit
Page 11
Chemistry 20 – Review Unit
Calculations Involving Mass and Moles
Determine the number of moles in 1000 g (1.000 kg) of each of the following. Show all work exactly as in
the example. Use correct SI symbols and significant digits.
Amount of
Substance (Common
Name)
1.
1000 g
(baking soda)
2.
1000 g
(washing soda)
3.
1000 g
(Epsom salts)
4.
1000 g
(TSP cleaner)
5.
1000 g
(contents in fire
extinguisher)
6.
7.
1000 mL
(distilled water)
Chemical
Name
Chemical
Formula
Molar Mass
Calculation of Moles
NaHCO3
sodium carbonate
MgSO47H2O
sodium phosphate
carbon dioxide
water
The container with the greatest number of moles in 1000 g of compound is ___________________ .
Chemistry 20 – Review Unit
Page 12
Chemistry 20 – Review Unit
Moles to Mass Calculations
Follow the example above to show all work and calculate the mass of each sample. Use correct significant
digits and SI symbols.
Amount of Substance
(Common Name)
Chemical Name
Chemical
Formula
potassium hydrogen
tartrate
KHC4H4O6
1.
0.100 mol
(cream of tartar)
2.
1.2 mol
(detergent filler)
3.
0.15 mol
white phosphorus
4.
55.56 mol
water
5.
0.025 mol
(formerly used as a
tooth decay
preventative)
6.
0.400 mol
(gypsum)
Chemistry 20 – Review Unit
Molar Mass
Mass
Na2SO410H2O
tin (II) fluoride
CaSO4  2H2O
Page 13