Kinetic Theory of Gases

Question 1

A real gas approximates to the behaviour of an ideal gas T/F

Answer 1

True

Question 2

Gases consist of a number of particles T/F

Answer 2

True

Question 3

Relative to their size, the particles in a gas are very close together T/F

Answer 3

False

Question 4

The particles of a gas move in a random pattern T/F

Answer 4

True

Question 5

The particles of a gas collide with one another T/F

Answer 5

True

Question 6

There are no attractive or repulsive forces between ideal gas particles T/F

Answer 6

True

Question 7

The particles of a real gas have an attraction between one another T/F

Answer 7

True

Question 8

What is Boyle’s law?

Answer 8

As the volume of a gas (container) is decreased at a constant temperature, its pressure will increase.

Question 9

What is Charles’ law?

Answer 9

At a constant pressure, the volume of a gas varies with its absolute temperature.

Question 10

What is Gay-Lussac’s law?

Answer 10

At a constant volume, the absolute pressure of a given mass of gas varies directly with the absolute temperature.

Question 11

The particles of an ideal gas are in constant motion T/F

Answer 11

True

Question 12

All the particles within a gas, at a fixed temperature, will be moving at the same speed T/F

Answer 12

False. Particles move at a range of speeds, governed by the Maxwell-Boltzmann distribution.

Question 13

The speed of gas particles varies inversely with temperature T/F

Answer 13

False. The speed and kinetic energy of gas particles will increase with temperature.

Question 14

The speed of gas particles is distributed normally T/F

Answer 14

False. The speeds are distributed normally with a right skew.

Question 15

With greater mass, the speed of gas particles is faster on average than those with smaller mass at a given temperature T/F

Answer 15

False. Gases with a higher molecular weight have a lower average speed at a given temperature than a gas of lower molecular weight.

Question 16

The speed of gas particles has a distribution that shifts to the left as molecular weight increases T/F

Answer 16

True. At a given temperature, a gas of higher molecular weight has particles moving at a lower average speed. The peak of the Maxwell-Boltzmann curve is therefore further to the left than the curve for a gas of a lower molecular weight.

Question 17

The speed of gas particles is directly proportional to the kinetic energy of those particles T/F

Answer 17

False. Kinetic energy varies with the square of the speed and is governed by the relationship Ek = 1/2mv2.

Question 18

The temperature of gas reflects the average potential energy of the gas particles T/F

Answer 18

False. Temperature is a reflection of the average kinetic energy of the gas particles.

Question 19

The temperature of gas falls as heat energy is removed from the gas T/F

Answer 19

True

Question 20

The temperature of gas when rising, causes the distribution of the speed of the gas particles to shift to the left T/F

Answer 20

False. As the temperature rises, the distribution of the speeds of the gas particles shifts to the right.

Question 21

The temperature of gas varies directly with the average speed of the gas particles

Answer 21

False. Temperature reflects the average kinetic energy which varies directly with the square of the average speed of the particles.

Question 22

The temperature of gas when rising, causes the rate of molecular collisions with the container walls to increase

Answer 22

True. As temperature rises the average speed of the particles will increase, resulting in more frequent collisions with the container walls and with other particles.

Question 23

The pressure of an ideal gas increases in a fixed container, if the kinetic energy of the particles increases T/F

Answer 23

True. As the kinetic energy increases, so too does the average speed of the gas particles. Therefore they collide more frequently with the sides of the container resulting in an increase in pressure.

Question 24

The pressure of an ideal gas falls if the volume of the container is decreased, as the gas particles have a smaller surface area to collide with T/F

Answer 24

False. As the volume of the container decreases, particles collide more frequently with the walls and the pressure therefore rises.

Question 25

The pressure of an ideal gas relies on the constant motion of its particles T/F

Answer 25

True. The constant motion of the gas particles leads to repeated collisions with the walls of the container. These collisions impart momentum which exerts a measurable force.

Question 26

The pressure of an ideal gas rises with temperature by virtue of a rise in the average kinetic energy of the gas particles, leading to more frequent collisions with the container walls T/F

Answer 26

True. A rise in kinetic energy results in an increase in average speed of the gas particles. This leads to an increase in the frequency of collisions with the container walls and, therefore, an increase in pressure.

Question 27

The pressure of an ideal gas remains constant as temperature rises, only if the container is not allowed to expand T/F

Answer 27

False. The container must be allowed to expand, otherwise the pressure increases with temperature due to more frequent collisions with the container walls.