Kinetic Theory and First Law of Thermodynamics MCQs

Question 1

When a gas is compressed by a piston, work is done:

Accepted Answer

on the gas by the surroundings

Answer

by the gas

Answer

only by heat

Answer

by nobody

Question 2

A syringe of air is sealed and the plunger is pushed in slowly. The molecules:

Accepted Answer

hit the walls more frequently

Answer

become smaller

Answer

move faster

Answer

hit the walls less frequently

Question 3

An ideal gas is heated from 200 K to 800 K. The average kinetic energy of its molecules is multiplied by:

Accepted Answer

4

Answer

2

Answer

0.25

Answer

16

Question 4

A gas at constant pressure 3 10^5 Pa changes volume from 0.5 m^3 to 0.8 m^3. The work done by the gas is:

Accepted Answer

90,000 J

Answer

9000 J

Answer

-90,000 J

Answer

9 10^5 J

Question 5

In pV = NkT, N stands for:

Accepted Answer

the number of molecules

Answer

the number of moles

Answer

Avogadro's constant

Answer

the number of collisions

Question 6

A gas exchanges no heat with its surroundings and does 150 J of work. The change in its internal energy is: (Use Q = Delta U + W, where Q = heat supplied to the gas and W = work done by the gas.)

Accepted Answer

-150 J

Answer

-300 J

Answer

-1500 J

Answer

-75 J

Question 7

0.5 mol of an ideal gas at 400 K occupies 0.01 m^3. Its pressure is (R = 8.31 J mol^-1 K^-1):

Accepted Answer

1.66 10^5 Pa

Answer

3.32 10^5 Pa

Answer

16,600 Pa

Answer

1.66 10^6 Pa

Question 8

A hammer hitting a nail repeatedly makes the nail warm. The nail's internal energy:

Accepted Answer

increases due to work done on it

Answer

becomes zero

Answer

decreases

Answer

stays constant

Question 9

The internal energy of a body is:

Accepted Answer

the sum of the random kinetic and potential energies of its molecules

Answer

the gravitational energy of the body

Answer

the heat it contains

Answer

only the kinetic energy of the whole body

Question 10

The average translational kinetic energy of a gas molecule is:

Accepted Answer

32kT

Answer

12kT

Answer

3kT

Answer

kT^2

Question 11

At constant volume, the pressure of a gas rises when it is heated because the molecules:

Accepted Answer

move faster, hitting the walls harder and more often

Answer

stop moving

Answer

attract each other

Answer

become bigger

Question 12

For an ideal gas, internal energy depends only on:

Accepted Answer

its temperature (for a fixed amount of gas)

Answer

its pressure only

Answer

its volume only

Answer

the container's shape

Question 13

A graph of pV against p for an ideal gas at constant temperature is:

Accepted Answer

a horizontal line

Answer

a straight line through the origin

Answer

a vertical line

Answer

a hyperbola

Question 14

The Boltzmann constant can be thought of as:

Accepted Answer

the gas constant for one molecule

Answer

the speed of a molecule

Answer

the charge on an electron

Answer

the gas constant for one mole

Question 15

At absolute zero, the kinetic energy of the molecules of an ideal gas would be:

Accepted Answer

minimum (zero for an ideal gas)

Answer

maximum

Answer

infinite

Answer

the same as at 0 °C

Question 16

In a car engine's power stroke, the hot gas:

Accepted Answer

does work on the piston

Answer

does no work

Answer

has work done on it

Answer

absorbs work from the crankshaft

Question 17

Which statement is correct?

Accepted Answer

Work done by the gas = −(work done on the gas)

Answer

Work done on the gas is always positive

Answer

Both are always zero

Answer

Work done by the gas = work done on the gas

Question 18

When a gas is heated at constant volume, all the heat supplied:

Accepted Answer

increases the internal energy

Answer

is converted to work

Answer

is lost

Answer

goes into the container

Question 19

A gas at 1 10^5 Pa, 3 L and 300 K is changed to 1.5 10^5 Pa and 450 K. Its new volume is:

Accepted Answer

3 L

Answer

6 L

Answer

1.5 L

Answer

12 L

Question 20

The zeroth law of thermodynamics states that if A and B are each in thermal equilibrium with C, then:

Accepted Answer

A and B are in thermal equilibrium with each other

Answer

A is hotter than B

Answer

C is hotter than both

Answer

A and B have equal masses

Question 21

A large iceberg at −10 °C can have more internal energy than a cup of boiling water because:

Accepted Answer

internal energy also depends on the amount of matter

Answer

ice is hotter

Answer

temperature measures total energy

Answer

boiling water has no energy

Question 22

The internal energy of a gas increases by 150 J while it does 100 J of work. The heat supplied to it is: (Use Q = Delta U + W, where Q = heat supplied to the gas and W = work done by the gas.)

Accepted Answer

250 J

Answer

2500 J

Answer

500 J

Answer

125 J

Question 23

A fixed mass of gas at 2 10^5 Pa occupies 3 L. At constant temperature it is changed to 12 L. The new pressure is:

Accepted Answer

50,000 Pa

Answer

8 10^5 Pa

Answer

1 10^5 Pa

Answer

25,000 Pa

Question 24

In a Boyle's law experiment, which quantity must be kept constant (besides temperature)?

Accepted Answer

the mass (amount) of gas

Answer

the pressure

Answer

the gradient

Answer

the volume

Question 25

A gas at constant pressure 1 10^5 Pa changes volume from 0.001 m^3 to 0.003 m^3. The work done by the gas is:

Accepted Answer

200 J

Answer

20 J

Answer

2000 J

Answer

-200 J

Kinetic Theory and First Law of Thermodynamics MCQs — Physics (page 5)

101. When a gas is compressed by a piston, work is done:

102. A syringe of air is sealed and the plunger is pushed in slowly. The molecules:

103. An ideal gas is heated from 200 K to 800 K. The average kinetic energy of its molecules is multiplied by:

104. A gas at constant pressure 3 10^5 Pa changes volume from 0.5 m^3 to 0.8 m^3. The work done by the gas is:

105. In pV = NkT, N stands for:

106. A gas exchanges no heat with its surroundings and does 150 J of work. The change in its internal energy is: (Use Q = Delta U + W, where Q = heat supplied to the gas and W = work done by the gas.)

107. 0.5 mol of an ideal gas at 400 K occupies 0.01 m^3. Its pressure is (R = 8.31 J mol^-1 K^-1):

108. A hammer hitting a nail repeatedly makes the nail warm. The nail's internal energy:

109. The internal energy of a body is:

110. The average translational kinetic energy of a gas molecule is:

111. At constant volume, the pressure of a gas rises when it is heated because the molecules:

112. For an ideal gas, internal energy depends only on:

113. A graph of pV against p for an ideal gas at constant temperature is:

114. The Boltzmann constant can be thought of as:

115. At absolute zero, the kinetic energy of the molecules of an ideal gas would be:

116. In a car engine's power stroke, the hot gas:

117. Which statement is correct?

118. When a gas is heated at constant volume, all the heat supplied:

119. A gas at 1 10^5 Pa, 3 L and 300 K is changed to 1.5 10^5 Pa and 450 K. Its new volume is:

120. The zeroth law of thermodynamics states that if A and B are each in thermal equilibrium with C, then:

121. A large iceberg at −10 °C can have more internal energy than a cup of boiling water because:

122. The internal energy of a gas increases by 150 J while it does 100 J of work. The heat supplied to it is: (Use Q = Delta U + W, where Q = heat supplied to the gas and W = work done by the gas.)

123. A fixed mass of gas at 2 10^5 Pa occupies 3 L. At constant temperature it is changed to 12 L. The new pressure is:

124. In a Boyle's law experiment, which quantity must be kept constant (besides temperature)?

125. A gas at constant pressure 1 10^5 Pa changes volume from 0.001 m^3 to 0.003 m^3. The work done by the gas is:

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