Which law states that the pressure of a gas held at constant volume is directly proportional to its Kelvin temperature?

The law that states that the pressure of a gas held at constant volume is directly proportional to its Kelvin temperature is Guy-Lussac's Law. This principle articulates that as the temperature of a gas increases, provided the volume remains unchanged, the pressure within that gas increases as well. It can be mathematically expressed as P/T = k, where P is the pressure, T is the absolute temperature in Kelvin, and k is a constant.

This relationship highlights the direct proportionality between temperature and pressure, meaning if you were to increase the temperature of a gas, the kinetic energy of the gas molecules also increases, resulting in more frequent and forceful collisions with the walls of their container, thereby increasing pressure. Understanding this law is essential for comprehending behaviors of gases under varying thermal conditions.