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Lab Section (circle one)
Chapter 7 Homework Problems
CHEM 1A
1. For each of the following substances describe the type of substance (strong/weak acid/base, other),
the type of compound (ionic, molecular), and how it exists in solution (completely/partially/not
dissociated/ionized), and the type of electrolyte (strong, weak, non).
Example HC2H3O2
Substance
Compound
In Soln.
Electrolyte
weak acid
molecular
partially ionized
weak
(a) NaOH
(b) C12H22O11
(c) NH3
(d) KBr
(e) HCl
2. Match the letter of a type of reaction with each example reaction. If more than one type of reaction
applies, provide all correct choices:
A. Combination
B. Decomposition
C. Single displacement
D. Double displacement
E. Combustion
F. Acid-base neutralization
G. Redox
_____
_____
_____
_____
_____
_____
_____
HClO4 + LiOH  H2O + LiClO4
2 H2O2  2 H2O + O2
2 C6H6 + 15 O2  12 CO2 + 6 H2O
Pb(NO3)2 + CaCl2  PbCl2 + 2 Ca(NO3)2
Zn + 2 AgCl  ZnCl2 + 2 Ag
2 HF + Na2CO3  H2O + CO2 + 2 NaF
2 Na + Br2  2 NaBr
3. Predict the products of the following equations, balance and check, and include phases:
(a) ___ Na (s) + ___ Cl2 (g) 
(b) ___ K (s) + ___ CaBr2 (aq) 
(c) ___ NiCl2 (aq) + ___ Na2S (aq) 
(d) ___ C2H2 (g) + ___ O2 (g) 
(e) ___ HCl (aq) + ___ Al(OH)3 (s) 
(f) ___ H2SO4 (aq) + ___ NaHCO3 (aq) 
4. When each of the following pairs of aqueous solutions is mixed, does a precipitation reaction occur?
If so, write the formula of the precipitate.
(a) Potassium carbonate + barium hydroxide
(b) Aluminum nitrate + sodium phosphate
5. For each of the following acid-base word equations:



Write a balanced formula equation. Include a balancing check, phases, and the label the type of
substance for the reactants (strong/weak acid/base) and products (ionic, molecular).
Also write a complete ionic equation and circle the spectator ions.
Finally, write the net ionic equation.
(a) Cesium hydroxide (aq) + nitric acid (aq) 
Formula Eqn.:
Complete Ionic Eqn.:
Net Ionic Eqn.:
(b) Calcium hydroxide (aq) + acetic acid (aq) 
Formula Eqn.:
Complete Ionic Eqn.:
Net Ionic Eqn.:
CHEM 1A – Chapter 7 – Page 2 of 4
6. Give the oxidation number of chromium in the following:
(a) CrO3
(b) Cr2O72–
(c) Cr2(SO4)3
7. Identify the following in the given redox equation:
8 NH3 (g) + 6 NO2 (g)  7 N2 (g) + 12 H2O (l)
Element being reduced: ______
Reducing Agent: ______
Element being oxidized: ______
Oxidizing Agent: ______
8. Write unbalanced oxidation and reduction half-reactions for the following processes:
Ox. ½ Rxn:
Red. ½ Rxn:
(a) Mn (s) + NO3– (aq)  Mn2+ (aq) + NO2 (g)
(b) Mn3+ (aq)  MnO2 (s) + Mn2+ (aq)
Note: 8(b) is a disproportionation reaction, a reaction in which the same substance is being both oxidized and
reduced, therefore, Mn3+ will appear on the reactant side of both ½ reactions
9. A person’s blood alcohol (C2H5OH) level can be determined by titrating a sample of blood plasma
with a potassium dichromate solution. The balance the following redox equation using the ½
reaction method, and show a check for the final balanced equation.
Cr2O72– + C2H5OH  Cr3+ + CO2
Reduction ½ reaction:
Oxidation ½ reaction:
Answer: _________________________________________________________
CHEM 1A – Chapter 7 – Page 3 of 4
10. Cream of tartar is potassium hydrogen tartrate. In C4H4O62– (tartrate), not all carbons have the
same oxidation number, two carbons are +3 and two carbons are 0. Balance the following redox
equation occurring in basic solution using the ½ reaction method, and show a check for the final
balanced equation.
C4H4O62– + ClO3–  CO32– + Cl–
Reduction ½ reaction:
Oxidation ½ reaction:
Answer: _________________________________________________________
CHEM 1A – Chapter 7 – Page 4 of 4