1. Chapter 7 Chemical Reactions

2. Which of the following is evidence that a chemical reaction has occurred?
7.1
Formation of a precipitate
Color change
Emission of light
Evolution of gas
All of the above
Answer: e

3. What is the coefficient for aluminum after the following equation is balanced? Al + O2 → Al2O3
7.4 1 2 3 4 6
Answer: d

4. What is the sum of the coefficients after the following equation is balanced? Al2O3 + H2SO4 → Al2(SO4)3 + H2O
7.5 4 6 12 8 10
Answer: d

5. When the following equation is balanced, what is the ratio of oxygen molecules to water molecules? C5H10 + O2 → CO2 + H2O
7.6
0.66
1.0
1.66
1.5
2.5
Answer: d

6. Which of the following compounds is INSOLUBLE in water?
7.8
Li2SO4
KOH
CaCO3
NH4NO3
NaCl
Answer: c

7. A substance dissolved in water that CANNOT conduct an electric current is called a
7.9
electrical compound.
strong electrolyte.
weak electrolyte.
weak cation.
Nonelectrolyte.
Answer: e

8. Identify the solid product formed from the balanced reaction of silver nitrate and calcium chloride.
7.11
CaNO3
AgCl
Ca(NO3)2
AgCl2
CaAg
Answer: b

9. Identify the solid product formed from the balanced reaction of potassium nitrate and barium chloride.
7.12
KCl
BaNO3
K2Cl
Ba(NO3)2
No solid is formed
Answer: e

10. Which of the following is a term in the complete ionic equation for the following reaction? LiOH(aq) + MgCl2(aq) →
7.14
Mg2+(aq)
OH–(aq)
Mg(OH)2(s)
Two of the above
All of the above
Answer: e

11. What salt is formed from the neutralization reaction between perchloric acid and potassium hydroxide?
7.18
Water
Sodium chloride
Potassium perchlorate
Potassium hydride
Potassium chlorate
Answer: c

12. When an acid reacts with a base, what product is typically formed?
7.19
Water
Sodium chloride
Oxygen
Carbon dioxide
Ammonium chloride
Answer: a

13. Which gas is released from the reaction of calcium carbonate with nitric acid?
7.20
Ammonia
Nitrogen dioxide
Hydrogen
Carbon dioxide
Nitrogen
Answer: d

14. How many molecules of carbon dioxide are produced from the combustion of one molecule of propane (C3H8)?
7.21 1 3 4 5 6
Answer: b

15. What type of reaction is the following? HgO (s) → Hg(l) + O2(g)
7.23
Synthesis/combination
Decomposition
Single displacement
Double displacement
Two of the above
Answer: a

16. What type of reaction is the following? 4Fe(s) + O2(g) → 2Fe2O3(s)
7.24
Oxidation–reduction
Combustion
Synthesis
All of the above
Answer: d

17. What type of reaction is the following
What type of reaction is the following? Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)
7.25
Precipitation
Acid–base
Double displacement
Single displacement
Answer: d

18. When NaHSO3 reacts with HNO3, what product is formed?
7.26
Na2SO4
H2SO4
SO2 gas
NaNO2
N2 gas
Answer: c

19. When compounds containing carbon and hydrogen react with oxygen in combustion reactions what is/are produced?
7.30
CH4(g) and O2(g)
H2(g) and O2(g)
CO2(g) and H2O(g)
C2H6(g)
None of the above
Answer: c