Name: Date: 1. On a cold day ( 3 C), the gauge pressure on a tire reads 2.0 atm. If the tire is heated to 27 C, what will be the absolute pressure of the air inside the tire? A) 2.0 atm B) 2.2 atm C) 2.4 atm D) 2.9 atm E) 3.3 atm 2. Two moles of a monatomic gas with an rms speed of 254 m/s are contained in a tank that has a volume of 0.15 m 3. If each gas particle has a mass of 6.642 10 26 kg, what is the absolute pressure of the gas? A) 2.3 10 5 Pa D) 5.4 10 4 Pa B) 1.1 10 4 Pa E) 3.4 10 4 Pa C) 6.8 10 4 Pa 3. A 1.00 10 2 m 3 flask contains 0.0160 kg of oxygen gas, O2, at 77.0 C. What is the pressure exerted on the inner walls of the flask by the oxygen gas? Note: the atomic mass of O is 15.9994 u. A) 3.19 10 4 Pa D) 5.79 10 5 Pa B) 1.45 10 5 Pa E) 4.87 10 6 Pa C) 2.90 10 5 Pa 4. Which one of the following statements concerning a collection of gas molecules at a certain temperature is true? A) All molecules move with the same velocity. B) Most of the molecules have the same kinetic energy. C) The lower the temperature, the greater are the molecular speeds. D) All molecules possess the same momentum. E) The molecules have a range of kinetic energies. 5. A sealed container has a volume of 0.020 m 3 and contains 15.0 g of molecular nitrogen (N2) which has a molecular mass of 28.0 u. The gas is at a temperature of 525 K. What is the absolute pressure of the nitrogen gas? A) 3.9 10 19 Pa D) 1.9 10 5 Pa B) 4.3 10 5 Pa E) 4.3 10 6 Pa C) 1.2 10 5 Pa Page 1
6. Heat is supplied to a sample of a monatomic ideal gas at 40 C. It is observed that the gas expands until its volume is doubled and the pressure drops to half of its original value. What is the final temperature of the gas? A) 10 C B) 20 C C) 40 C D) 80 C E) 1600 C 7. What is the density of methane, CH4, (molecular mass = 16 u) at STP? A) 0.357 kg/m 3 B) 0.386 kg/m 3 C) 0.431 kg/m 3 D) 0.712 kg/m 3 E) 0.951 kg/m 3 8. A tank contains 135 moles of the monatomic gas argon at a temperature of 15.3 C. How much energy must be added to the gas to increase its temperature to 45.0 C? A) 2.50 10 3 J B) 3.33 10 4 J C) 5.00 10 4 J D) 5.70 10 5 J E) 7.50 10 6 J 9. The temperature of a monatomic ideal gas with a mass per mole of 0.00750 kg/mol is 294 K. The absolute pressure of the gas is 1.05 10 5 Pa when its volume is 1.31 10 3 m 3. What is the mass of the gas? A) 8.04 10 5 kg D) 7.66 10 4 kg B) 1.92 10 4 kg E) 1.19 10 3 kg C) 4.22 10 4 kg 10. How many molecules are in 0.064 kg of sulfur dioxide, SO2? (atomic masses: S = 32 u; O = 16 u) A) 3 B) 64 C) 2.00 10 24 D) 6.02 10 23 E) 3.85 10 25 11. At what temperature would one mole of molecular oxygen (O2) have 5.0 10 3 J of translational kinetic energy? Note: the atomic mass of O is 16 u. A) 130 C B) 390 C C) 400 C D) 670 C E) 1000 C 12. Complete the following statement: The atomic mass unit (u) is defined so that 1 u is exactly equal to the mass of A) a single hydrogen atom. D) 1/32 of an oxygen molecule. B) 1/4 of a helium molecule. E) 1/12 of a carbon-12 atom. C) 1/16 of an oxygen-16 atom. Page 2
13. In the space between two stars, the temperature of a gas cloud is 12 K; and the density of the gas is 1.2 10 8 atom/m 3. What is the absolute pressure of the gas? A) 2.0 10 30 Pa D) 1.2 10 6 Pa B) 1.2 10 28 Pa E) 1.4 10 4 Pa C) 2.0 10 17 Pa 14. What is the internal energy of 1.75 kg of helium (atomic mass = 4.00260 u) with a temperature of 100 C? A) 4.65 10 3 J B) 5.44 10 5 J C) 2.03 10 6 J D) 8.16 10 6 J E) 1.22 10 7 J 15. Which of the following samples exhibits the highest degree of entropy? A) a diamond crystal D) a block of paraffin B) ammonia vapor E) liquid oxygen C) a block of graphite Use the following to answer question 16: An ideal monatomic gas expands isobarically from state A to state B. It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. 16. What is the temperature of the gas when it is in state B? A) 437 K B) 573 K C) 927 K D) 1200 K E) 1473 K 17. Under which one of the following conditions would a Carnot heat engine be 100% efficient? A) The engine discharges heat at 0 K. D) The engine can be operated in reverse. B) The engine uses no heat. E) The engine uses an ideal gas. C) The engine does no work. Page 3
18. Which one of the following processes represents a decrease in entropy? A) the melting of ice B) the sublimation of carbon dioxide C) the evaporation of perfume D) the vaporization of liquid helium E) the condensation of steam on a kitchen window 19. An ideal gas is taken from state A to state B through process shown on the pressure-volume graph. How much heat is added to the gas in this process? A) zero joules B) 1.0 10 4 J C) 2.4 10 4 J D) 6.0 10 4 J E) This cannot be determined since n and T are not specified. Use the following to answer question 20: A container holding 1.2 kg of water at 20.0 C is placed in a freezer that is kept at 20.0 C. The water freezes and comes into thermal equilibrium with the interior of the freezer. 20. What is the minimum amount of electrical energy required by the refrigerator to carry out this process if it operates between reservoirs at temperatures of 20.0 C and 20.0 C? A) 63 000 J B) 77 000 J C) 87 000 J D) 348 000 J E) 549 000 J 21. One mole of a monatomic gas at 400 K is reversibly taken to half of its original volume by an isobaric process. How much work is done by the gas? A) +1700 J B) 1700 J C) +3300 J D) 3300 J E) 8300 J 22. A heat engine operates in a Carnot cycle between reservoirs of temperatures 1000 K and 400 K. It is found to discharge 20 J of heat per cycle to the cold reservoir. What is the work output per cycle? A) 10 J B) 20 J C) 30 J D) 40 J E) 50 J 23. A gasoline engine with an efficiency of 0.40 generates 1500 W of power. If a liter of gasoline has an energy content of 3.7 10 7 J, how many liters of gasoline does the engine consume each hour? A) 0.36 B) 0.48 C) 1.4 D) 2.8 E) 6.9 Page 4
24. Which one of the following statements best describes the operation of a heat engine? A) A heat engine uses input heat to perform work and rejects excess heat to a lower temperature reservoir. B) A heat engine performs work and generates an equal amount of heat in a cyclic process. C) A heat engine transfers heat from a lower temperature reservoir to a higher temperature reservoir through work performed on the system. D) A heat engine transfers heat from a higher temperature reservoir to a lower temperature reservoir through work performed on the system. E) A heat engine decreases the entropy of the universe by generating an equal amount of heat and work. 25. Determine the quantity of heat added to 3.5 moles of the ideal gas argon if the temperature increases from 75 C to 225 C during an isobaric process. Note: The molar specific heats of argon are CV = 3.0 cal/k mol and CP = 5.0 cal/k mol. A) 2600 cal B) 2100 cal C) 1600 cal D) 1100 cal E) 750 cal 26. A Carnot engine has a heat input of 3700 J and heat exhaust of 1400 J. What is the ratio of the Kelvin temperature of the hot reservoir to that of the cold reservoir, TH/TC? A) 3.6 B) 0.38 C) 1.6 D) 0.62 E) 2.6 27. Brad spends four hours watching football on television and does 1090 J of work. In the process, his internal energy decreases by 2990 J. Determine the value of Q, including the algebraic sign. A) 1900 J B) +1900 J C) 2990 J D) +4080 J E) 4080 J Use the following to answer question 28: An ideal monatomic gas expands isobarically from state A to state B. It is then compressed isothermally from state B to state C and finally cooled at constant volume until it returns to its initial state A. Page 5
28. How much work is done on the gas in going from B to C? A) 2.5 10 6 J B) 5.5 10 6 J C) 4.5 10 6 J D) 6.5 10 6 J E) 8.0 10 6 J 29. Neon is a monatomic gas with a molar heat capacity at constant volume of 12.66 J/(mol K). Two moles of neon gas enclosed in a constant volume system receive 5250 J of heat. If the gas was initially at 293 K, what is the final temperature of the neon? A) 200 K B) 300 K C) 400 K D) 500 K E) 600 K 30. A match ignites within in an oxygen-filled cylinder that has a movable piston. The piston is moved so quickly that no heat escapes. What kind of change is demonstrated in this process? A) an isobaric change D) an isochoric change B) an adiabatic change E) a change of heat capacity C) an isothermal change 31. Which one of the following pressure-volume graphs represents an isochoric process? A) (a) B) (b) C) (c) D) (d) E) (e) 32. A fixed amount of ideal gas is compressed adiabatically. Which entry in the table below correctly depicts the sign of the work done, the change in the internal energy, and the heat exchanged with the environment? work done change in internal energy heat exchanged A) positive negative zero B) negative zero positive C) negative negative zero D) positive positive zero E) negative positive zero Page 6
Answer Key 1. E 2. B 3. B 4. E 5. C 6. C 7. D 8. C 9. C 10. D 11. A 12. E 13. A 14. C 15. B 16. D 17. A 18. E 19. C 20. C 21. B 22. C 23. A 24. A 25. A 26. E 27. A 28. B 29. D 30. B 31. D 32. E Page 7