2.40. The work in the adiabatic process is n = (iv -
-1)/(y — 1) In n = 1.4 times greater.
2.41. T = To [(71 + 1)2/401-1)/2.
2.42. v = 112yRT1(y — 1) M = 3.3 km/s.
2.43. Q = RAT (2 — y)/(y — 1).
2.45. Cr, = R (n — 7)/(n —
— 1); Cn < 0 for 1 < n < T.
2.46. C = R (n y)1 (n — 1) (y — 1) = —4.2 J/(K•mol), where
n= In 13/In a.
2.47. (a) Q = R (n — y) AT 1(n — 1) (y — 1) = 0.11 kJ; (b)
A = —RAT1(n — 1) = 0.43 kJ.
(a)
(6)
I
Fig. 13.
2.48. (a) AU = aV,;(112 — 1)/(y — 1); (b) A = 112aq (112 — 1);
(c) C = 1/2R (y + 1)/(y — 1).
2.49. (a) C = —R/(y — 1); (b) TV(Y-1-)/2 = const; (c) A =
= 2RT0 (1 —
-Y)12)/(7 - 1).
2.50. (a) A = (1 — a) RAT; (b) C = R/(y — 1) + R (1 — a);
C < 0 for a > y/(y — 1).
2.51. (a) A = AU (y — 1)/a; Q = AU El
(y — 1)/al; (b) C
= R1(y — 1) + R/a.
2.52. (a) C = Cv + R/aV; (b) C = Cv + R/(1 + aV).
2.53. (a) C = TR/(y — 1) + aR/P017;
(b) AU = Po (V2 -
- Vi)/(y — 1); A = Po (V2 — V1) -1- a In (v 21v1); Q = w (V2
— 1) + a In (V2/V1).
2.54. (a) C = Cp + RTolaV;
(b) Q = aEp (V2 — V1) +
RT 0 In (V2/V1).
2.55. (a) Ve -21 7R = const; (b) TeR/fw = const; (c) V — aT
= const.
2.56. (a) A = a In II —RT0 ( 1— 1)/(y —1); (b) p- VY ea (v-i)/pv,.
= const.
V2
—b
b
—
1
2.57. A=RT In Fi
—+ a
(
V2 VI
-----)
where a and b are Van
der Waals constants.
2.58. (a) AU= alV alV 2= 0.11 kJ; (b) Q=RT in V2 - b =
=3.8 kJ.