Assume molecules have an average diameter of 1.20 x 10-10m. How many times larger is the mean free path than the diameter at STP? (Assume the pressure is 1.01 x 105N/m2 and the temperature is 20°C. 0°C = 273.15K) Select the correct answer.

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20% 20% 20%20%20%

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1. 5200

2. 5300

3. 5000

4. 5700

5. 5800

A box contains about 10.0 x 1021 hydrogen atoms at room temperature (21°C). Determine the thermal energy of these atoms. (R = 8.315J/mol·K. 0°C = 273.15K) Select the correct answer.

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20% 20% 20%20%20%

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1. 61J

2. 6.6J

3. 5.8J

4. 68J

5. 64J

When we consider a thin horizontal layer of the atmosphere, of thickness dy, of area A, with pressure P on the bottom, with an average mass m per molecule, and nV molecules per unit volume, the magnitude of the difference of the pressure at the top and bottom of the layer is given by dP = _____ . Select the correct answer.

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20% 20% 20%20%20%

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1. mgndy

2. mgnVdy

3. mgAdy

4. mgnVAdy

5. mgnVAPdy

A container having a volume of 1.2 m3 holds 2.0 moles of helium gas at 80°C. If the helium behaves like an ideal gas, the average kinetic energy per molecule is _____ . (kB =1.38 x 10-23 J/K. 0°C = 273.15 K) Select the correct answer.

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20% 20% 20%20%20%

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1. 7.3 x 10-21J

2. 9.3 x 10-22J

3. 8.9 x 10-20J

4. 8.6 x 10-21J

5. 8.4 x 10-20J

Assume 4.0 moles of a diatomic gas has an internal energy of 20 kJ. Determine the temperature of the gas after it has reached equilibrium. (R = 8.315J/mol·K) Select the correct answer.

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1. 240 K

2. 250 K

3. 30 K

4. 270 K

5. 170 K

The internal energy of n moles of an ideal gas depends on _____ . Select the correct answer.

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20% 20% 20%20%20%

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1. one state variable T

2. two state variables T and V

3. two state variables T and P

4. three state variables T, P and V

5. four variables R, T, P and V