If the temperature increases in a sample of gas at constant volume, then its
a. volume increases.
b. pressure decreases.
c. pressure increases.
d. volume decreases.

If the temperature increases in a sample of gas at constant volume, then its pressure increases. The answer is letter C. When you increase the temperature of a given volume of gas; you are actually increasing the kinetic energy of the molecules. The incessant battering into the walls of the container causes an increase in pressure within the container. And the more pressure it exerts, the more collisions between the gas particles takes place. It also follows the combined gas law wherein pressure is directly proportional to the temperature and inversely proportional to volume.