What relationship exists between pressure and temperature in Kelvin for a gas?

The relationship between pressure and temperature in Kelvin for a gas is directly proportional. This means that as the temperature of a gas increases, its pressure also increases, provided that the volume and the amount of gas remain constant. This relationship is described by Gay-Lussac's Law, which states that the ratio of the pressure of a gas to its absolute temperature (in Kelvin) remains constant for a given amount of gas at constant volume.

In practical terms, if you were to increase the temperature of a gas in a sealed container, the gas particles would gain kinetic energy and move more vigorously, resulting in more collisions with the walls of the container. This increased frequency and force of collisions would cause an increase in pressure. The crucial factor here is that temperature must be measured in Kelvin because the Kelvin scale starts at absolute zero, where all molecular motion stops, thus providing an accurate depiction of gas behavior under varying thermal conditions. This prevents any misleading results that could occur if using other temperature scales, such as Celsius or Fahrenheit, which can include negative values.