Problem Set #1 / Unit 1
Equation Writing
1. First, classify the type of reaction as neutralization (N), precipitation (P),
ionization (I), dissociation (D), acid anhydride (AA), base anhydride (BA),
gas-forming (GF), or no reaction (NR). Second, write both total molecular and net
ionic equations for the reaction that occurs when:
a. potassium hydroxide and nitric acid solutions are mixed.
b. solutions of iron (III) chloride and sodium hydroxide are mixed.
c. iron (III) hydroxide is dissolved by excess sulfuric acid solution.
d. aqueous copper (II) sulfate is mixed with aqueous sodium sulfide.
e. aluminum hydroxide is dissolved in hydrochloric acid solution.
f. a solution of calcium chloride is mixed with a solution of sodium carbonate.
g. hydrochloric acid and sodium hydroxide solutions are mixed.
h. a solution of aluminum chloride is added to a solution of silver nitrate.
i. solutions of silver nitrate and sodium chromate are mixed.
j. sodium hydroxide pellets are dissolved in water.
k. sodium dichromate crystals are dissolved in water.
l. sulfur trioxide gas is bubbled through water.
m. ammonia gas is added to water.
n. magnesium hydroxide is dissolved by an excess of sulfuric acid solution.
o. excess barium hydroxide solution is added to a solution of phosphoric acid.
p. hydrochloric acid is added to water.
q. sodium oxide is added to water.
r. solutions of magnesium sulfate and barium hydroxide are mixed.
s. nitrogen dioxide gas is bubbled through water.
t. calcium oxide is added to water.
u. solutions of zinc nitrate and ammonium sulfate are mixed.
v. phosphoric acid is added to water. (3 reactions)
w. carbon dioxide is bubbled through water.
x. acetic acid is added to water.
y. calcium hydroxide is dissolved in water.
z. a solution of calcium hydroxide is mixed with a solution of hydrochloric acid.
aa. solutions of hydrochloric acid and sodium carbonate are mixed. Bubbles
are produced.
bb. solutions of ammonium chloride and sodium hydroxide are mixed. An odor
is observed.
Chemistry II
Cary Academy
W.G. Rushin
1
2. Write balanced equations (show work) for the oxidation-reduction
reaction that occurs when:
a. MnO4- reacts with C2O42- in basic solution to produce MnO2 solid and CO32-.
b. permanganate ion reacts with hydrogen peroxide (H2O2, pay attention to
the oxidation state of oxygen in the form of peroxide) in acidic solution to
produce Mn2+ and oxygen gas.
c. permanganate ion reacts with chloride ion in acidic solution to produce
chlorine gas and Mn2+.
d. chloride ion reacts with dichromate ion in acidic solution to produce Cr3+
and chlorine gas.
e. Fe2+ reacts with permanganate ion in acidic solution to produce Fe 3+ and Mn2+.
f. Mn2+ reacts with Br2(l) in basic solution to produce MnO2 solid and bromide ion.
g. copper metal reacts with nitric acid to produce copper (II) nitrate,
nitrogen monoxide gas, and water.
Steps for Balancing Oxidation-Reduction Reactions
1. Assign oxidation numbers (write them below the equation to avoid
confusing them with the actual charges on ions).
2. Identify which atoms change oxidation number and insert
temporary coefficients so that there are the same number of each
atom on both sides of the equation.
3. Calculate the total change of electrons for both the oxidation and
reduction.
4. Balance electron gain and loss by multiplying the coefficients by
appropriate factors.
5. Balance by inspection if substances are not charged, otherwise
proceed to step 6.
6. Balance net charge by adding H3O+ (for an acidic solution) or OH(for a basic solution).
7. Balance hydrogens or oxygens by adding water then check if the
other is balanced.
Chemistry II
Cary Academy
W.G. Rushin
2