CHEM 1200

Practice Test 4

Note: These questions are representative of the types of questions you can expect on the test. The actual test will be longer, typically between 20-40 questions. You will need to bring a SCANTRON answer sheet to each test.

1. Calculate Eocell for the following reaction:

2Fe2+(aq) + Cd2+(aq) ® 2Fe3+(aq) + Cd(s)

a. - 0.37 V
b. + 0.37 V
c. - 1.17 V
d. + 1.17 V
e. none of the above

2. Pick out the one reaction below that will occur spontaneously

a. Mg2+ + Ca ® Mg + Ca2+
b. Au + 3K+ ® Au3+ + 3K
c. 2Al3+ + 3Fe ® 2Al + 3Fe2+
d. Cu + 2H+ ® Cu2+ + H2

3. Given the following standard reduction potentials in acid solution

Al3+ + 3e- ® Al (s)                        Eo = -1.66 V
AgBr (s) + e- ® Ag (s) + Br-         Eo = + 0.07 V
Sn4+ + 2e- ® Sn2+                        Eo = + 0.14 V
Fe3+ + e- ® Fe2+                          Eo = + 0.77 V

Which of the following is the strongest oxidizing agent?

a. Fe3+
b. Fe2+
c. Br-
d. Al3+
e. Al

4. Which one of the following reagents is capable of transforming Cu2+(1 M) to Cu(s)?

a. I- (aq)
b. Ni (s)
c. Ag+ (1M)
d. Al3+ (1M)
e. H+ (1M)

5. Which of the following is the strongest oxidizing agent under standard conditions?

a. Ag+ (aq)
b. H2 (g)
c. H+ (aq)
d. Cl2 (g)
e. Al3+ (aq)

6. Which of the following species has the highest entropy (DSo) at 25oC?

a. H2O (s)
b. CO (g)
c. NaCl (s)
d. H2O (l)
e. Fe (s)

7. Which response includes all the following processes that are accompanied by an increase in entropy.

a. I2(s) ® I2(g)
b. 2I(g) ® I2(g)
c. 2NH3(g) ® N2(g) + 3H2(g)
d. Mg2+(aq) + 2OH- (aq) ® Mg(OH)2(s)

e. Both a and c 8. Calculate DS for the reaction

SO2(s) + NO2(g) ® SO3(g) + NO(g)
Given the following absolute entropies.

SO2(g)             248.5
SO3(g)              256.2
NO(g)               210.6
NO2(g)             240.5

a. 53.6 J/K
b. - 53.6 J/K
c. -22.2 J/K
d. 474.8 J/K
e. - 474.8 J/K

9. In which process is the system entropy increasing?

I. Expansion of a gas into a vacuum.
II. Vaporization of a liquid.
III. Precipitation of a solid from solution

a. All of them
b. only II and III
c. only I and III
d. only I and II
e. only III

Check your answers