Name___________________________________## Gases

DIRECTIONS: Circle the answer that best completes each statement.

1. Which of the following are described by a linear graph with a slope of 1 (assume 1 mole of an ideal gas)? (a) PV versus V with constant T (b) P versus T with constant V (c) T versus V with constant P (d) V versus P with constant T a&b a&c b&c b&d 2. For an ideal gas at constant temperature: (a) doubling the pressure doubles the volume. (b) Tripling the volume triples the pressure. (c) Reducing the pressure to one third its original value triples the volume. (d) The volume occupied by gas molecules is zero. a&d b&c a,b&c c&d 3. Ideal gas particles (a) move randomly. (b) have no kinetic energy. (c) have no mass. (d) repel each other at high pressure. all of a&c a,c&d b&d the above 4. The values of a and b in the table below for an ideal gas are, respectively, P (atm) V (cm^{3}) T (^{o}C) ------------------------------------------------------- 1 6240 25 2 a 25 1 b 55 (a) 3120 and 6870 (b) 3120 and 5670 (c) 12,480 and 2840 (d) 12,480 and 13,700 a b c d 5. At a certain temperature the diffusion rate of helium is 0.21 m/s. Under the same conditions (a) the diffusion rate of hydrogen is 0.15 m/s. (b) the diffusion rate of hygrogen is 0.30 m/s. (c) the diffusion rate of CH_{4}will be higher. (d) the diffusion rate of NH_{3}will be lower. none of a&c b&c b&d the above 6. The values of a and b in the table below for one mole of an ideal gas are, respectively, P (atm) V (dm^{3}) T (^{o}C) -------------------------------------------------------- 1.0 50.0 75 1.0 110 a 2.0 b 75 (a) 165^{o}C and 100 dm^{3}(b) 165^{o}C and 25 dm^{3}(c) 493^{o}C and 100 dm^{3}(d) 493^{o}C and 25 dm^{3}a b c d 7. The ideal gas equation is (a) PV = nT / R (b) P / V = nRT (c) PVn = RT (d) PV = nRT a b c d 8. At STP, (a) T = 0^{o}C, P = 1 atm (b) T = 100^{o}C, P = 100 kPa (c) the volume occupied by an ideal gas is inversely proportional to its molecular weight. (d) the volume occupied by an ideal gas is 22.4L. a&c a&d b&c b&d 9. The values of a and b in the table below for an ideal gas are, respectively, n P (atm) T (^{o}C) V (L) ------------------------------------------------------------------------------------- 2 2.0 0 a 2 2.0 100 b (a) 44.8 L and 15.3 L (b) 11.2 L and 8.2 L (c) 22.4 L and 8.2 L (d) 22.4 L and 30.6 L a b c d 10. 3.0 L of nitrogen trifluoride gas is reacted with 3.0 L of steam to produce the gases HF, NO, and NO_{2}at constant temperature and pressure. Assuming a 100% yield, which of the following statements are true? (a) A total of 8.0 L of gas will be produced. (b) A total of 5.0 L of gas will be produced. (c) A total of 6.0 L of gas will be produced. (d) All of the nitrogen trifluoride will be consumed. a&d b&d c only b only 11. Which of the following are true statements? (a) R = (PV) / (nT) (b) The closer a gas is to the liquid state, the more it will deviate from the ideal gas law. (c) H_{2}0 behaves more ideally than H_{2}. (d) A balloon filled with argon is smaller than an identical balloon filled with helium (assume constant T, P, & n) all of a&b b&d a,b&d the above 12. Which gases have the same rate of diffusion? (a) C_{2}H_{2}(b) N_{2}(c) CO (d) CH_{4}all of a,b&c b&c c&d the above 13. The pressure of helium inside a steel container can be lowered by (a) adding methane gas to it. (b) adding steam to it. (c) increasing the temperature. (d) decreasing the temperature. a&d b&d b&c d only 14. One mole of oxygen at STP (a) has a mass of 16 g. (b) has a volume of 1.0 L. (c) contains 6.02 X 10^{23}molecules (d) has a pressure of 760 mmHg. all of a&c a,b,&c c&d the above 15. Two 1.0 L steel cylinders each contains 1.0 mole of gas at 0^{o}C. One cylinder contains CO_{2}, and the other, O_{2}. Both cylinders (a) have the same pressure. (b) have the same mass. (c) have the same density. (d) are at STP. a only b only b&d b,c&d 16. Which of the following gases are less dense than air at STP? (a) CH_{4}(b) C_{3}H_{8}(c) NH_{3}(d) NO_{2}a only a,b&c c&d a&c 17. For the reaction C_{(s)}+ O_{2(g)}---------> CO_{2(g)}at constant T and P, which of the following are true statements? (a) 2.0 L of O_{2}will yield 3.0 L of CO_{2}(b) 1.0 mole of C_{(s)}will yield 1.0 L of CO_{2}(c) 1.0 mole of C_{(s)}will yield 22.4 L of CO_{2}(d) 6.0 L of O_{2}will yield 3.0 L of CO_{2}a&b d only c only none of the above 18. Which of the following are true statements? (a) The value for the gas constant is 0.0821 L.atm/mol.K. (b) One mole of O_{2}occupies 22.4 L at STP. (c) 1 atm = 760 mmHg (d) 0^{o}C = -273 K a,b&c b,c&d a,c&d all of the above 19. The density of NO_{2}gas at STP is (a) 2.05 g/L (b) 46.0 g/L (c) less than the density of NH_{3}at STP (d) less than the density of SO_{2}at STP a&d b&c a&c b&d 20. The rate of diffusion of helium is 3.1592 times greater than the rate of diffusion of (a) N_{2}(b) argon (c) CH_{4}(d) carbon monoxide a b c d

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Answers:

1. b&c 2. c&d 3. a&c 4. a 5. b&d 6.d 7. d 8. a&d 9. d

10. a&d 11. a&b 12. b&c 13. d only 14. c&d 15. a only

16. a&c 17. none 18. all 19. a&d 20. b

© 1996 by Frank Virzi