Why does the volume increase when the temperature increases?

Answer 1

Directly proportional

Well the reason is:

as you usually know, when you increase volume, pressure should decrease.

but in a case of constant pressure, as volume increases, well, pressure stays the same.

So how does that work? The only reason pressure wouldn't change is if the temperature will increase, allowing molecules of gas to move more rapidly, and therefore creating pressure that stays constant, as the volume increases. (but if you would keep increasing temperature under constant volume, pressure would actually increase).

Answer 2

When temperature increases, the average kinetic energy of the particles in a substance also increases. This increase in kinetic energy causes the particles to move faster and spread out, leading to an increase in volume. This relationship is described by Charles's Law, which states that at constant pressure, the volume of a gas is directly proportional to its temperature.

Answer 3

Temperature is really the measure of kinetic energy, or how quickly individual atoms and molecules are moving, so when the temperature is increased, they move faster and farther apart.

Answer 4

At constant temperature, pressure is inversely proportional. There is no change in internal energy, and all the thermal input to the gas goes into the work of expansion.