Gen. Chem. - Chap. 18
Choose the correct answer for each question.
 

1Given the following cell notation for an electrochemical cell: Pt(s) | H2(g) | H+(aq) | | Ag+(aq) | Ag(s)
What is the balanced overall cell reaction?
2 H+(aq) + 2 Ag+(aq) ----> H2(g) + 2 Ag(s)
H2(g) + 2 Ag(s) ----> H+(aq) + 2 Ag+(aq)
H2(g) + Ag+(aq) ----> H+(aq) + Ag(s)
H2(g) + 2 Ag+(aq) -----> 2 H+(aq) + 2 Ag(s)

2Given the following equation: 2 H2(g) + O2(g) ----> 2 H2O (l) the oxidizing agent is...
H2O
H2
O2
not an oxidation-reduction equation

3Which of the followng is the strongest reducing agent?

Co2+ + 2e- ----> Co Ered = -0.280V
Ni2+ + 2e- -----> Ni Ered = -0.236V
Mn2+ + 2e- -----> Mn Ered = -1.182V
Ni2+
Ni
Mn
Co

4Given the reduction potentials in the question above, which of the following reactions are spontaneous at standard concentrations?
1.Ni + Co2+ -----> Ni2+ + Co
2. Mn2+ + H2 -----> Mn + 2 H+
3. Co + 2 H+ ----> Co2+ + H2
1 only
3 only
1 and 2
2 and 3

5If E is + for a reaction, then K for that reaction at standard conditions must be...
+
-
greater than 1
less than 1

6Calculate dG for the equation: Mn + Co2+ -----> Mn2+ + Co
given F= 96.5 kJ/mol-V and...
Co2+ + 2e- ----> Co Ered = -0.280V
Mn2+ + 2e- -----> Mn Ered = -1.182V
+174 kJ
+25.6 kJ
-87.0 kJ
-174 kJ

7Calculate E for the reaction : Mn(s) + Co2+(aq)(0.1M) -----> Mn2+(aq)(0.01M) + Co(s) (HINT: use the E you calculated above to answer this question)
+0.902 V
+0.932 V
+0.990 V
+1.360 V

8The minimum amount of voltage required to perform the electrolysis of CuCl2 into Cu(s) and Cl2(g) is...
(Ered Cu2+ = +0.339 V and Ered Cl2(g) = +1.360 V)
1.021 V
1.699 V
0.678 V
1.360 V

9Caculate the no. of moles of Ni plated from a Ni2+ solution in 10 min. by a current of 10 A. (1 mol e- = 96,480 C)
Ni2+ + 2e- ----> Ni
0.031 mol
0.062 mol
0.12 mol
9.6 mol

10The main disadvantage of a lead storage battery is...
the inability to hold an appreciable amount of charge
a high mass-to-charge ratio
low voltage
expensive manufacturing processes