Which of the following explains why the pressure of a gas increases when the temperature increases (volume remaining constant)?
a) the kinetic energy of gas molecules increase
b) the velocity of gas molecules increases
c) the collision frequency of gas molecules increases
d) all of the above
e) none of the above

D) All of the above

Explanation:

When the temperature increases, it means that the kinetic energy of the gas molecules had increased too because the temperature is a way to measure this kinetic energy. When this happens, the velocity of gas molecules increases because kinetic energy and velocity are directed related:

Where Ek is the kinetic energy, m is the mass and v is the velocity.

If the velocity increases, there will be more collisions between molecules, so, with more collisions, the pressure, which is the measure of the force a gas makes in the system, will increase. So, all the answers explain why the pressure of a gas increases when the temperature increases.