Question 1

How many molecules are in a sample of 10-3 mol?

Accepted Answer

A)   6.02 x 1018
B)   6.02 x 1020
C)   6.02 x 1022
D)   6.02 x 1023
E)   cannot tell without knowing the molecular mass B

Question 2

The heat capacity at constant volume of an ideal gas depends on:

Accepted Answer

A)   the temperature
B)   the pressure
C)   the volume
D)   the number of molecules
E)   none of the above D

Question 3

Over 1 cycle of a cyclic process in which a system does net work on its environment:

Accepted Answer

A)   the change in the pressure of the system cannot be zero
B)   the change in the volume of the system cannot be zero
C)   the change in the temperature of the system cannot be zero
D)   the change in the internal energy of the system cannot be zero
E)   none of the above E

Question 4

A real gas is changed slowly from state 1 to state 2. During this process no work is done on or by the gas. This process must be:

Accepted Answer

A)   isothermal
B)   adiabatic
C)   occurring at constant volume
D)   occurring at constant pressure
E)   a closed cycle with point 1 coinciding with point 2

Question 5

The pressures p and volumes V of the five ideal gases, with the same number of molecules, are given below. Which has the highest temperature?

Accepted Answer

A)   p = 1 * 105 Pa and V = 10cm3
B)   p = 3 * 105 Pa and V = 6 cm3
C)   p = 4 * 105 Pa and V = 4 cm3
D)   p = 6 * 105 Pa and V = 2 cm3
E)   p = 8 * 105 Pa and V = 2 cm3

Question 6

Use R = 8.2 * 10-5 m3. atm/mol . K and NA = 6.02 *1023 mol-1. The approximate number of air molecules in a 1 m3 volume at room temperature (300 K) and atmospheric pressure is:

Accepted Answer

A)   41
B)   450
C)   2.4 * 1025
D)   2.7 * 1026
E)   5.4 * 1026

Question 7

The "Principle of equipartition of energy" states that the internal energy of a gas is shared equally:

Accepted Answer

A)   among the molecules
B)   between kinetic and potential energy
C)   among the relevant degrees of freedom
D)   between translational and vibrational kinetic energy
E)   between temperature and pressure

Question 8

The number of degrees of freedom of a rigid diatomic molecule is:

Accepted Answer

A)   2
B)   3
C)   4
D)   5
E)   6

Question 9

For a given change in temperature, the change in the internal energy of an ideal gas:

Accepted Answer

A)   also depends on the change in pressure
B)   also depends on the change in volume
C)   depends on whether the process is adiabatic or not
D)   depends on whether the process occurs at constant pressure or not
E)   can be calculated assuming the volume is constant

Question 10

An ideal gas undergoes an isothermal process starting with a pressure of 2 * 105 Pa and a volume of 6 cm3. Which of the following might be the pressure and volume of the final state?

Accepted Answer

A)   1 * 105 Pa and 10cm3
B)   3 * 105 Pa and 6 cm3
C)   4 * 105 Pa and 4 cm3
D)   6 * 105 Pa and 2 cm3
E)   8*105 Pa and 2 cm3

Question 11

In an adiabatic expansion,

Accepted Answer

A)   the temperature of the gas does not change.
B)   the gas does work on the environment, and the internal energy of the gas decreases.
C)   the environment does work on the gas, and the internal energy of the gas increases.
D)   the volume of the gas does not change.
E)   the pressure of the gas does not change.

Question 12

Oxygen (molar mass = 32 g) occupies a volume of 12 liters when its temperature is 20 $\degree$C and its pressure is 1 atm. Using R = 0.082 liter.atm/mole.K, calculate the mass of the oxygen:

Accepted Answer

A)   6.4 g
B)   11 g
C)   16 g
D)   32 g
E)   64 g

Question 13

As the pressure in an ideal gas is increased isothermally the average molecular speed:

Accepted Answer

A)   increases
B)   decreases
C)   increases at high temperature, decreases at low
D)   decreases at high temperature, increases at low
E)   stays the same

Question 14

If the molecules in a tank of hydrogen have the same rms speed as the molecules in a tank of oxygen, we may be sure that:

Accepted Answer

A)   the pressures are the same
B)   the hydrogen is at the higher temperature
C)   the hydrogen is at the greater pressure
D)   the temperatures are the same
E)   the oxygen is at the higher temperature

Question 15

For a gas at thermal equilibrium the average speed v, the most probable speed vp, and the root-mean-square speed vrms are in the order:

Accepted Answer

A)   vp rms 
B)   vrms p 
C)   v rms p
D)   vp rms
E)   v p rms

Question 16

The temperature of n moles of an ideal monatomic gas is increased by $\Delta$T at constant pressure. The energy Q absorbed as heat, change $\Delta$Eint in internal energy, and work W done by the environment are given by:

Accepted Answer

A)   Q = (5/2) nR Δ\DeltaΔ T,  Δ\DeltaΔ Eint = 0, W = -nR Δ\DeltaΔ T
B)   Q = (3/2) nR Δ\DeltaΔ T,  Δ\DeltaΔ Eint = (5/2) nR Δ\DeltaΔ T, W = -(3/2) nR Δ\DeltaΔ T
C)   Q = (5/2) nR Δ\DeltaΔ T,  Δ\DeltaΔ Eint = (5/2) nR Δ\DeltaΔ T, W = 0
D)   Q = (3/2) nR Δ\DeltaΔ T,  Δ\DeltaΔ Eint = 0, W = -nR Δ\DeltaΔ T
E)   Q = (5/2) nR Δ\DeltaΔ T,  Δ\DeltaΔ Eint = (3/2) nR Δ\DeltaΔ T, W = -nR Δ\DeltaΔ T

Question 17

Assume that helium behaves as an ideal monatomic gas. If 2 moles of helium undergo a temperature increase of 100 K at constant pressure, how much energy has been transferred to the helium as heat?

Accepted Answer

A)   1700 J
B)   2500 J
C)   4200 J
D)   5000 J
E)   6700 J

Question 18

The pressure of an ideal gas is doubled in an isothermal process. The root-mean-square speed of the molecules:

Accepted Answer

A)   does not change
B)   increases by a factor of
C)   decreases by a factor of
D)   increases by a factor of 2
E)   decreases by a factor of 1/2

Question 19

As the volume of an ideal gas is increased at constant pressure the average molecular speed:

Accepted Answer

A)   increases
B)   decreases
C)   increases at high temperature, decreases at low
D)   decreases at high temperature, increases at low
E)   stays the same

Question 20

Evidence that molecules of a gas are in constant motion is:

Accepted Answer

A)   winds exert pressure
B)   two gases interdiffuse quickly
C)   warm air rises
D)   energy as heat is needed to vaporize a liquid
E)   gases are easily compressed

Exam 19: The Kinetic Theory of Gases

How many molecules are in a sample of 10^-³ mol?

The heat capacity at constant volume of an ideal gas depends on:

Over 1 cycle of a cyclic process in which a system does net work on its environment:

A real gas is changed slowly from state 1 to state 2. During this process no work is done on or by the gas. This process must be:

The pressures p and volumes V of the five ideal gases, with the same number of molecules, are given below. Which has the highest temperature?

Use R = 8.2 * 10^-5 m³. atm/mol . K and N_A = 6.02 *10²³ mol^-1. The approximate number of air molecules in a 1 m³ volume at room temperature (300 K) and atmospheric pressure is:

The "Principle of equipartition of energy" states that the internal energy of a gas is shared equally:

The number of degrees of freedom of a rigid diatomic molecule is:

For a given change in temperature, the change in the internal energy of an ideal gas:

An ideal gas undergoes an isothermal process starting with a pressure of 2 * 10⁵ Pa and a volume of 6 cm³. Which of the following might be the pressure and volume of the final state?

In an adiabatic expansion,

Oxygen (molar mass = 32 g) occupies a volume of 12 liters when its temperature is 20 $\degree$ C and its pressure is 1 atm. Using R = 0.082 liter.atm/mole.K, calculate the mass of the oxygen:

As the pressure in an ideal gas is increased isothermally the average molecular speed:

If the molecules in a tank of hydrogen have the same rms speed as the molecules in a tank of oxygen, we may be sure that:

For a gas at thermal equilibrium the average speed v, the most probable speed v_p, and the root-mean-square speed v_rms are in the order:

The temperature of n moles of an ideal monatomic gas is increased by $\Delta$ T at constant pressure. The energy Q absorbed as heat, change $\Delta$ E_int in internal energy, and work W done by the environment are given by:

Assume that helium behaves as an ideal monatomic gas. If 2 moles of helium undergo a temperature increase of 100 K at constant pressure, how much energy has been transferred to the helium as heat?

The pressure of an ideal gas is doubled in an isothermal process. The root-mean-square speed of the molecules:

As the volume of an ideal gas is increased at constant pressure the average molecular speed:

Evidence that molecules of a gas are in constant motion is:

Exam 19: The Kinetic Theory of Gases

How many molecules are in a sample of 10-3 mol?

The heat capacity at constant volume of an ideal gas depends on:

Over 1 cycle of a cyclic process in which a system does net work on its environment:

A real gas is changed slowly from state 1 to state 2. During this process no work is done on or by the gas. This process must be:

The pressures p and volumes V of the five ideal gases, with the same number of molecules, are given below. Which has the highest temperature?

Use R = 8.2 * 10-5 m3. atm/mol . K and NA = 6.02 *1023 mol-1. The approximate number of air molecules in a 1 m3 volume at room temperature (300 K) and atmospheric pressure is:

The "Principle of equipartition of energy" states that the internal energy of a gas is shared equally:

The number of degrees of freedom of a rigid diatomic molecule is:

For a given change in temperature, the change in the internal energy of an ideal gas:

An ideal gas undergoes an isothermal process starting with a pressure of 2 * 105 Pa and a volume of 6 cm3. Which of the following might be the pressure and volume of the final state?

In an adiabatic expansion,

Oxygen (molar mass = 32 g) occupies a volume of 12 liters when its temperature is 20 °\degree° C and its pressure is 1 atm. Using R = 0.082 liter.atm/mole.K, calculate the mass of the oxygen:

As the pressure in an ideal gas is increased isothermally the average molecular speed:

If the molecules in a tank of hydrogen have the same rms speed as the molecules in a tank of oxygen, we may be sure that:

For a gas at thermal equilibrium the average speed v, the most probable speed vp, and the root-mean-square speed vrms are in the order:

The temperature of n moles of an ideal monatomic gas is increased by Δ\DeltaΔ T at constant pressure. The energy Q absorbed as heat, change Δ\DeltaΔ Eint in internal energy, and work W done by the environment are given by:

Assume that helium behaves as an ideal monatomic gas. If 2 moles of helium undergo a temperature increase of 100 K at constant pressure, how much energy has been transferred to the helium as heat?

The pressure of an ideal gas is doubled in an isothermal process. The root-mean-square speed of the molecules:

As the volume of an ideal gas is increased at constant pressure the average molecular speed:

Evidence that molecules of a gas are in constant motion is:

How many molecules are in a sample of 10^-³ mol?

Use R = 8.2 * 10^-5 m³. atm/mol . K and N_A = 6.02 *10²³ mol^-1. The approximate number of air molecules in a 1 m³ volume at room temperature (300 K) and atmospheric pressure is:

An ideal gas undergoes an isothermal process starting with a pressure of 2 * 10⁵ Pa and a volume of 6 cm³. Which of the following might be the pressure and volume of the final state?

Oxygen (molar mass = 32 g) occupies a volume of 12 liters when its temperature is 20 $\degree$ C and its pressure is 1 atm. Using R = 0.082 liter.atm/mole.K, calculate the mass of the oxygen:

For a gas at thermal equilibrium the average speed v, the most probable speed v_p, and the root-mean-square speed v_rms are in the order:

The temperature of n moles of an ideal monatomic gas is increased by $\Delta$ T at constant pressure. The energy Q absorbed as heat, change $\Delta$ E_int in internal energy, and work W done by the environment are given by: