In the equation V1/T1 = V2/T2, what two variables are directly proportional?

The equation V1/T1 = V2/T2 is known as Charles's Law, which describes the relationship between the volume and absolute temperature of a gas when pressure is held constant. This law specifically states that the volume of a gas is directly proportional to its absolute temperature (measured in Kelvin).

This means that if you increase the temperature of the gas, its volume will also increase, as long as pressure remains constant. Conversely, if the temperature decreases, the volume will also decrease. The relationship is linear, so as one variable increases, the other also increases at a constant rate.

In this context, the direct proportionality highlights the fundamental behavior of gases in response to temperature changes within an ideal situation, influencing many applications in thermodynamics and chemistry. Understanding this relationship is crucial for problem-solving in gas behavior and related phenomena.