How does temperature affect the volume of a gas?

Temperature directly affects the volume of a gas; as temperature increases, the volume of a gas also increases, and vice versa.

In more detail, this relationship between temperature and volume is explained by the kinetic theory of gases. This theory states that gases are made up of a large number of tiny particles that are in constant, random motion. The temperature of a gas is directly related to the average kinetic energy of these particles. When the temperature of a gas increases, the kinetic energy of the particles also increases. This means that the particles move faster and collide more frequently and with greater force against the walls of their container. These increased collisions cause the volume of the gas to expand.

Conversely, when the temperature of a gas decreases, the kinetic energy of the particles decreases as well. The particles move slower and collide less frequently and with less force against the walls of their container. This results in a decrease in the volume of the gas.

This relationship between temperature and volume is known as Charles's Law. Named after Jacques Charles, who first stated the principle in the 1780s, it states that the volume of a given amount of gas is directly proportional to its temperature on the absolute temperature scale (Kelvin), provided the pressure remains constant. This means that if you double the temperature of a gas, you will also double its volume, as long as the pressure is kept constant.

In practical terms, this means that if you heat a balloon, it will expand as the gas inside it increases in volume. Conversely, if you cool a balloon, it will shrink as the gas inside it decreases in volume. This principle is used in many everyday applications, such as hot air balloons and refrigeration systems.