Physical Chemistry Third Edition

K Answers to Numerical Exercises and Odd-Numbered Numerical Problems 1311

∆U(rev)−11536 J

w(rev)−11536 J

2.21

a. CP,m(He) 20 .786 J K Mol−^1

CP,m(Ne) 20 .786 J K mol−^1

CP,m(Ar) 20 .786 J K mol−^1

5 R/ 2  20 .786 J K mol−^1

b. CP,m(N 2 ) 29 .124 J K mol−^1

CP,m(O 2 ) 29 .376 J K mol−^1

CP,m(CO) 29 .142 J K mol−^1

7 R/ 2  29 .101 J K mol−^1

2.22

CP,m(298.15 K) 37 .1JK−^1 mol−^1

CP,m(500 K) 45 .1JK−^1 mol−^1

CP,m(1000 K) 52 .1JK−^1 mol−^1

5 R/ 2  20 .786 J K mol−^1

2.24

CP,m 25 .10JK−^1 mol−^1

3 R 24 .944JK−^1 mol−^1. 0.6% difference

2.26

At 298.15 K,CP,m 29 .37JK−^1 mol−^1

At 500 K,CP,m 31 .42JK−^1 mol−^1

At 1000 K,CP,m 34 .0JK−^1 mol−^1

At 2000 K,CP,m 38 .3JK−^1 mol−^1

2.27

a. ∆U935 J

b. ∆H1559 J

q3086 J

w−2151 J

2.28

Tf5229 K

2.29

Tf7263 K

2.30
∆U◦ 54 .530 kJ mol−^1

2.31
∆Tcal 3 .771 K

2.32

∆H≈−199 kJ mol−^1

From∆fHvalues,∆H◦− 174 .264 kJ mol−^1

Chapter 2 Problems

2.1

wsurr2079 J

2.3

w 4 .79 J

2.7

b. w1765 J

c. wsurr507 J

2.9

I− 8. 3145 × 104 Pa− 0 .8206 atm

2.11

∆T 0 .117 K

2.13

a. q−w4543 J

b. q−w2975 J

2.15

q 120 .9kJ

w− 8 .771 kJ

2.17

E 9. 0 × 109 J mol−^1

v 4. 2 × 105 ms−^1

2.19

q 33 .35 kJ

w 0 .92 J

∆U 33 .35 kJ

2.21

(1) q−w9221 J,∆U 0

(2) q−w6916 J

(3) q−w3040 J

2.23

a. μJ− 1. 43 × 104 Km−^3 mol

b. T 2 282 K

2.25

P 2  0 .947 atm

2.27

a. T 2  25 .7K

b. V 2  0 .0705 m−^3