Edited by Sydney Green
Rebecca Groner
Chapter 8 Review Problems:
1) Define the following terms
a) acid-a substance that produces hydrogen ions
when dissolved in water 1-easy
b) base-a substance that produces hydroxide ions
in water 1-easy
c) precipitate-the solid that forms after some
chemical reactions 1-easy
d) soluble solid-a solid that is able to dissolve 1easy
e) insoluble solid-a solid that cannot dissolve 1easy
f) salt-a dissolved ionic compound formed by
two other aqueous solutions after a chemical
reaction 1-easy
2) What is a synthesis reaction? Give an example. A
synthesis reaction is when the two elements or
compounds combine. The equation for water (2H2 + O2)
is an example of such a reaction. 2-meduim
3) What makes an acid or base a strong acid or strong
base? When a base or acid is a strong electrolyte it’s
called a “strong base” or a “strong acid.”2-medium
4) Define the following types of reactions and give an
example:
a) oxidation-reduction reaction When there’s a
transfer of electrons due to the reaction. 2Cs +
F2  2CsF. 2-medium
b) combustion reaction When a reaction produces
energy/heat and a flame results. C + O2  CO2
2-medium
c) double-displacement reaction The associations
of the reactants are reversed as products. KOH
+ HCl  KCl + H2O. 2-medium
d) acid-base reaction When an acid and base
react. The reactants form water. HCl + NaOH
 H2O + NaCl. 2-medium
e) decomposition reaction When a substance
decomposes into two different elements or
compounds. 2HgO 2Hg + O2 2-medium
5) Define the term “driving force.” Name a “driving force” of
a chemical reaction. A driving force is a change that
creates a reaction’s outcome. Forces: formation of a gas,
transfer of electrons, formation of a solid (precipitate),
formation of water. 1-easy
6) What’s the difference between a molecular equation and
an ionic equation? A molecular equation shows all the
reactants and products and their forms but not their
individual charge, which helps to explain a react more
clearly and is used in the ionic equation. 1-easy
7) Why would you use a net ionic equation? One would use
a net ionic equation when they want to find out how a
precipitate came about and look closely at some of the
ions in the reaction. 2-medium
8) Define the term “spectator ions.” “Spectator ions” are the
ions that are disregarded in the net ionic equation
because they don’t directly help/stay present in the
reaction. 1-easy
9) Explain precipitation in terms of a chemical reaction.
Precipitation is when a solid forms in a reaction. 1-easy
10) Define “solubility.” Solubility is the ability of a product
to dissolve, which requires a chemical reaction 1-easy
11) What’s the relation between oxidation-reduction
reactions and combustion reactions? Combustion
reactions are a specific type of oxidation-reduction
reactions. 2-medium
12) State whether the following reactions are synthesis,
decomposition, or combustion reactions:
a) 2H2O(l)  2H2(g)+O2(g) decomposition 2-medium
b) 2Na(s)+Cl2(g)  2NaCl(s) synthesis 2-medium
c) C3H8(g) +5O2(g)  3CO2(g) + 4H2O(g) combustion 2-
medium
d) N2(g)+O2 (g) 2NO(g) synthesis 2-medium
13) Classify the following equations. Some of them have
more than one answer.
a) 2Mg(s) + O2(g)  2MgO2(s) redox, synthesis 3-hard
b) HCl(aq) + KOH(aq)  H2O(l) + KCl(aq) acid-base,
double-replacement 3-hard
c) H2SO4(aq) + Cu(s)  CuSO4(aq) + H2(g) redox,
single-replacement 3-hard
14) Write the molecular formula for sulfuric acid when it
combines with lead (II) nitrate. Circle the precipitate.
H2SO4(aq) + Pb(NO3)2(aq)  2HNO3(aq) + PbSO4(s). PbSO4 is
the precipitate. 2-meduim
15) Write a, b, and c for silver nitrate and calcium iodide.
a) the molecular equation AgNO3 (aq) + CaI2 (aq) 
AgI(s) + CaNO3 (aq) 2-medium
b) the net ionic equation Ag+(aq), + NO3- (aq), + Ca2+
+ 2+
(aq) + 2I (aq)  Ag I (s) + Ca (aq) + 2NO3 (aq) 2medium
c) the balanced net ionic equation Ag+(aq) + I-(aq)
 AgI(s) 2-medium
16) Balance the following equations and state whether it’s
reduction oxidation, single-replacement, acid base or
precipitation:
a) Cl2 (g) + F2  ClF(g) 3-hard
Cl2 (g) + F2  2ClF(g). Oxidation-
reduction.
b) HBr(aq)+ NaOH(aq)  NaBr(aq) + H2O(l) 3-hard
Already balanced. Acid-base reaction.
17) Would gold (III) chloride and sodium hydroxide (based
on their chemical composition) form a precipitation
reaction? How do you know? 3-hard Yes, the net ionic
equation for gold (III) chloride and sodium hydroxide
shows that they would form Au(OH)3(s), a precipitate. Au
3+(aq) +Cl3 -1(aq) + 3Na +1(aq) + OH -1(aq)  Au(OH)3(s) +
3Na+(aq) + 3Cl-(aq)
18) Balance the following decomposition reaction and then
identify the products: 2-medium
BaCO3 (s)  BaO(s) + CO2(g)
2BaCO3 (s)  2BaO(s) + 2CO2(g). Barium
oxide and carbon dioxide are the two
products that BaCO3 decomposed into.
65/10.5=6.19