Consider two containers with the same volume and temperature. Container One holds dry air--a mixture of nitrogen and oxygen. Container Two holds moist air. The moist air has the same ratio of nitrogen to oxygen molecules, but also contains water vapor. According to the ideal gas law, if the pressures are equal, the weight of the gas in Container One will be
a. lighter than the gas inside the second container.
b. equal to the weight of the gas in the second container.
c. heavier than the gas inside the second container.
d. all the above are incorrect because the pressures cannot be equal.
[Ques. 2] If the temperature of a volume of ideal gas increases for 100C to 200C, what happens to the average kinetic energy of the molecules?
a. It halves. b. It doubles.
c. It increases but less that double. d. It increases more than double.
[Ques. 3] The noble gases, listed by increasing molecular weight, are He, Ne, Ar, Kr, Xe, and Rn. If samples of 1 mole each of these gases are placed in separate containers and heated to 300 K, which gas has the greatest internal energy and the molecules of which gas have the highest rms speed?
a. The He has the greatest internal energy, and the Rn has the greatest rms speed.
b. The Rn has the greatest internal energy, and the He has the greatest rms speed.
c. All the gases have the same internal energy, and the Rn has the greatest rms speed.
d. All the gases have the same internal energy, and the He has the greatest rms speed.
[Ques. 4] The temperature of a quantity of ideal gas in a sealed container is increased from 0C to 273C. What happens to the rms speed of the molecules of the gas as a result of this temperature increase?
a. It does not change since rms speed is independent of temperature.
b. It increases but it less than doubles.
c. It doubles.
d. It quadruples.
[Ques. 5] The internal energy of a monatomic ideal gas is equal to which of the following?
a. (3/2)PV
b. (3/2)nT/V
c. 3 T/P
d. none of the above
[Ques. 6] A quantity of a monatomic ideal gas expands to twice the volume while maintaining the same pressure. If the internal energy of the gas were U0 before the expansion, what is it after the expansion?
a. U0
b. 2U0
c. 4U0
d. The change in temperature must also be known to answer this question.
[Ques. 7] What is the internal energy of 50 moles of neon gas (molecular mass = 20 u) at 20.0C? (R = 8.31 J/mol/K)
a. 1.8E+5 J
b. 8.1E+5 J
c. 2.1E+3 J
d. 1.2E+4 J
e. It depends on the container size, which is not given.
[Ques. 8] John rapidly pulls a plunger out of a cylinder. As the plunger moves away, the gas molecules bouncing elastically off the plunger are
a. rebounding at a higher speed than they would have if the plunger weren't removed.
b. rebounding at a lower speed than they would have if the plunger weren't removed.
c. rebounding at the same speed as they would have if the plunger weren't removed.
d. Whether they speed up or slow down depends on how fast the plunger is removed.
[Ques. 9] For an ideal gas of a given mass, if the pressure remains the same and the volume increases,
a. the average kinetic energy of the molecules decreases.
b. the average kinetic energy of the molecules stays the same.
c. the average kinetic energy of the molecules increases.
d. Nothing can be determined about the molecular kinetic energy.
[Ques. 10] If the temperature of an ideal gas contained in a box is increased
a. the average velocity of the molecules in the box will be increased.
b. the average speed of the molecules in the box will be increased.
c. the distance between molecules in the box will be increased.
d. all of the above.
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