446
Answers to Problems of the A Groups
6. approximately 8.0%
9. -3.14 kcal
7. (a) CO and H 2 O are each 22.9%
10. -44.9 kcal
CO 2 and H 2 are each 27.1%
(b) C0 2 and H 2 are each 14.5%
u> ^
+3 ^\ f
ca
CO is 2.2%
(b) -
3L4 kcal
H 2 O is 68.8%
12. 8.05 x 10~
6 atrrr
1
8. (a) 10.5%
(b) 18.3%
(c) 0.704 NT
1
CHAPTER 17
1. Arrange beakers and salt bridge as in Figure 17-1. Use solutions and electrodes as
follows.
(a) Mg electrode in Mg
2+ solution in left beaker; Ag electrode in Ag
+ solution in
right beaker.
(b) Cu electrode in Cu
2+ solution in left beaker. With pool of Hg in bottom of right
beaker containing Hg|
+ solution, use Pt electrode as in right beaker of Figure
17-2.
(c) In both beakers use Pt electrode as in right beaker of Figure 17-2. In left beaker
put solution containing Sn
2+ and Sn
4+ ; in right beaker put solution containing
S 2 Oj(- and SOf-.
(d) In both beakers use Pt electrode as in right beaker of Figure 17-2. In left beaker
put solution containing Sn
2+ and Sn
4+ ; in right beaker put solution containing
Br~, and enough Br 2 to have a slight excess of liquid Br 2 lying on the bottom.
(e) Fe electrode in Fe
2+ solution in left beaker. Pt electrode in solution of Fe
2+ and
Fe
3+ as in right side of Figure 17-2.
2. (a) Mg/Mg
2+ //Ag
+ /Ag
(d) Pt/Sn
2+ ,Sn
4+ //Br-,Br 2 /Pt
(b) Cu/Cu
2+ //Hg 2
2+ /Hg,Pt
(e) Fe/Fe
2+ //Fe
2+ ,Fe
3+ /Pt
(c) Pt/Sn
2+ ,Sn
4+ //S 2 Oi-,S0 4
2 -/Pt
3. (/) (a) 3.16 v
07) (a) 3.16 v
(b) 0.45 v
(b) 0.51 v
(c) 1.86 v
(c) 1.92 v
(d) 0.92 v
(d) 1.04 v
(e) 1.21 v
(e) 1.33 v
4. (a) 8.66 x 10
106
(d) 1.36 x 10
31
(b) 1.69 x 10
15
(e) 8.86 x 10
40
(c) 8.79 x 10
62
5. (a) -146 kcal
(d) -42.4 kcal
(b) -20.8 kcal
(e) -55.8 kcal
(c) -85.8 kcal
6. At negative electrode:
2e- + Fe(OH) 2 ?± 2OH~ + Fe