The temperature of a gas sample in a rigid container is raised.?

Question

Why does the pressure the gas exerts on the container walls increase?

A. The molecules are in contact with the walls for briefer intervals.
B. The molecular masses increase.
C. The molecules lose more kinetic energy each time they strike the wall.
D. The molecules have higher average speeds and so strike the walls more often with greater momentum.

Answer 1

Temperature is a function of the average Kinetic Energy of the particles of the system.
As the temperature of the gas increases, the average KE of the gas molecules increase.
Kinetic Energy, you will remember, is a function of the velocity of the particle, so as the KE increases, so does the speed of the particles. Thus, the higher the temperature, the faster the molecules are moving.

When the temperature of the gas is increased, the gas molecules start moving faster and thus collide with the walls of the container more often and with more momentum than before….thus increasing the measured pressure inside the container.

The correct answer is choice d).

Answer 2

When we deal with the expansion or contraction of gases, we are dealing with the changes in pressure, temperature and volume.
The Combined Gas Law states P1V1 / T1 = P2V2 / T2. There are, therefore, three physical laws we need regarding gases: isobaric, isothermal, and isometric expansion.
Boyle's Law of Isothermal expansion is P1V1 = P2V2.
Charles' Law of Isobaric Expansion is V1/T1 = V2/T2.
Gay-Lussac's Law is P1T2 = P2T1.
Your question relates to isometric expansion -- the pressure and temperature of a volume of gas increase together but the volume stays the same in the container: Gay-Lussac's Law can also be stated as P1/T1 = P2/T2. As the temperature increases, the molecules begin to move with greater speed and in larger orbits within the container. Since the number of molecules is limited by the volume of the container, they begin pushing against one another faster and harder, raising the pressure.

Answer 3

D. The speed is proportional to the square root of the absolute temperature.