第 1 頁, 共 6 頁 Chap20 1. Test Bank, Question 5 Which of the following is NOT a state variable? Work Internal energy Entropy Temperature Pressure 2. Test Bank, Question 18 Let denote the change in entropy of a sample for an irreversible process from state A to state B. Let S R denote the change in entropy of the same sample for a reversible process from state A to state B. Then: > S R = S R < S R = 0 S R = 0 3. *Chapter 20, Problem 11 In an experiment, 170 g of aluminum (with a specific heat of 900 J/kg K) at 77.0 C is mixed with 51.0 g of water (with a specific heat of 4186 J/kg K) at 48.0 C, with the mixture thermally isolated. (a) What is the equilibrium temperature, in Celsius? What are the entropy changes of (b) the aluminum, (c) the water, and (d) the aluminum-water system? (a) Number 60.106874478152 Units C (b) Number -7.565551139572 Units J/K (c) Number 7.900110003206 Units J/K (d) Number 0.334558863633 Units J/K 4. *Chapter 20, Problem 14 (a) For 2.14 moles of a monatomic ideal gas taken through the cycle in Fig. 20-24, where V 1 = 8.0V 0 what is W/p 0 V 0 as the gas goes from state a to state c along path abc? What is ΔE int /p 0 V 0 in going (b) from b to c and (c) through one full cycle? What is ΔS in going (d) from b to c and (e) through one full cycle?

第 2 頁, 共 6 頁 (a) Number 7 Units This answer has no units (b) Number 36 Units This answer has no units (c) Number 0 Units This answer has no units (d) Number 36.979540712309 Units J/K (e) Number 0 Units J/K 5. Chapter 20, Problem 17 For n moles of a diatomic ideal gas taken through the cycle in Figure 20-25 with the molecules rotating but not oscillating, what are (a)p 2 /p 1, (b)p 3 /p 1, and (c)t 3 /T 1? For path 1 to 2, what are (d)w/nrt 1, (e)q/nrt 1, (f) ΔE int /nrt 1, and (g) ΔS/nR? For path 2 to 3, what are (h)w/nrt 1, (i)q/nrt 1, (j) ΔE int /nrt 1, (k) ΔS/nR? For path 3 to 1, what are (l)w/nrt 1, (m)q/nrt 1, (n) ΔE int /nrt 1, (o) ΔS/nR? (a) Number 0.333333333333 Units This answer has no units (b) Number 0.214798004992 Units This answer has no units (c) Number 0.644394014977 Units This answer has no units (d) Number 1.098612288668 Units This answer has no units (e) Number 1.098612288668 Units This answer has no units (f) Number 0 Units This answer has no units (g) Number 1.098612288668 Units This answer has no units (h) Number 0 Units This answer has no units (i) Number -0.889014962558 Units This answer has no units (j) Number -0.889014962558 Units This answer has no units (k) Number -1.098612288669 Units This answer has no units (l) Number -0.889014962558 Units This answer has no units (m) Number 0 Units This answer has no units (n) Number -0.889014962558 Units This answer has no units (o) Number 0 Units This answer has no units

第 3 頁, 共 6 頁 6. Test Bank, Question 21 For all irreversible processes involving a system and its environment: the entropy of the system does not change the entropy of the system increases the total entropy of the system and its environment does not change the total entropy of the system and its environment increases none of the above 7. Test Bank, Question 27 According to the second law of thermodynamics: heat energy cannot be completely converted to work work cannot be completely converted to heat energy for all cyclic processes we have dq/t < 0 the reason all heat engine efficiencies are less than 100% is friction, which is unavoidable all of the above are true 8. Test Bank, Question 30 A heat engine operates between a high temperature reservoir at T H and a low temperature reservoir at T L. Its efficiency is given by 1 T L /T H : only if the working substance is an ideal gas only if the engine is reversible only if the engine is quasi-static only if the engine operates on a Stirling cycle no matter what characteristics the engine has 9. *Chapter 20, Problem 33 Figure 20-29 shows a reversible cycle through which 1.00 mole of a monatomic ideal gas is taken. Process bc is an adiabatic expansion, with p b = 11.0 atm and V b = 3.00 x 10-3 m 3. For the cycle, find (a) the energy added to the gas as heat, (b) the energy leaving the gas as heat, (c) the net work done by the gas, and (d) the efficiency of the cycle.

第 4 頁, 共 6 頁 (a) Number 4857.6515625 Units J (b) Number 1828.148437500000 Units J (c) Number 3029.503125 Units J (d) Number 0.623655913978 Units This answer has no units 10. *Chapter 20, Problem 29 Figure 20-27 a reversible cycle through which 1.08 mol of a monatomic ideal gas is taken. Assume that p = 2.06 p 0, V = 2.35 V 0,p 0 = 2.14 10 5 Pa, and V 0 = 0.0241 m 3. What is the efficiency of the cycle? Number 0.166666666667 Units This answer has no units Significant digits are disabled; the tolerance is +/-2% 11. *Chapter 20, Problem 43 Figure 20-32 represents a Carnot engine that works between temperatures T 1 = 425 K and T 2 = 165 K and drives a Carnot refrigerator that works between temperatures T 3 = 345 K and T 4 =250 K. What is the ratio of Q 3 /Q 1?

第 5 頁, 共 6 頁 2.22156 Significant digits are disabled; the tolerance is +/-2% 12. *Chapter 20, Problem 52 Suppose 1.6 mol of a monatomic ideal gas initially at 6.3 L and 290 K is heated at constant volume to 590 K, allowed to expand isothermally to its initial pressure, and finally compressed at constant pressure to its original volume, pressure, and temperature. During the cycle, what are (a) the net energy entering the system (the gas) as heat and (b) the net work done by the gas? (c) What is the efficiency of the cycle? (a) Number 11561.007947485059 Units J (b) Number 1583.641547485058 Units J (c) Number 0.136981269685 Units This answer has no units 13. Test Bank, Question 35 An inventor suggests that a house might be heated by using a refrigerator to draw energy as heat from the ground and reject energy as heat into the house. He claims that the energy supplied to the house can exceed the work required to run the refrigerator. This: is impossible by first law is impossible by second law would only work if the ground and the house were at the same temperature is impossible since heat flows from the (hot) house to the (cold) ground is possible 14. *Chapter 20, Problem 64 (a) A Carnot engine operates between a hot reservoir at 378 K and a cold one at 315 K. If the engine absorbs 575 J as heat per cycle at the hot reservoir, how much work per cycle does it deliver? (b) If the engine working in reverse functions as a refrigerator between the same two reservoirs, how much work per cycle must be supplied to remove 339 J as heat from the cold reservoir?

第 6 頁, 共 6 頁 (a) Number 95.833333333333 Units J (b) Number 67.8 Units J 15. Chapter 20, Problem 75 System A of three particles and system B of five particles are in insulated boxes like that in Figure 20-17. What is the least multiplicity W of (a) system A and (b) system B? What is the greatest multiplicity W of (c)a and (d)b? What is the greatest entropy of (e)a and (f)b? Fig. 20-17 Problem 67. (a) Number 1 Units This answer has no units (b) Number 1 Units This answer has no units (c) Number 3 Units This answer has no units (d) Number 10 Units This answer has no units (e) Number 1.516084958362E-23 Units J/K (f) Number 3.177567428332E-23 Units J/K