# Can you explain Gay Lussac's law in terms of the kinetic molecular theory?

May 1, 2014

Gay-Lussac's Law states that, in a closed system of fixed volume, as the temperature of a gas increases, the pressure increases as well and this can be explained using kinetic molecular theory, or how the movement of individual gas particles affects the behavior of a gas as a whole.

#### Explanation:

Gay-Lussac's Law states that, in a closed system of fixed volume, as the temperature of a gas increases, the pressure increases as well. This can be explained using kinetic molecular theory, or how the movement of individual gas particles affects the behavior of a gas as a whole.

Temperature is a measure of the average kinetic energy of a substance, or, how much motion atoms/particles have as a result of heat energy. As the temperature of a substance rises, its molecules are moving faster or more energetically.

In a gas, when particles are in a confined space, faster movement of gas molecules will increase the number of collisions that molecules have with each other or with the container. Think of trying to move through a crowded room at a party: if you walk through slowly, you can avoid bumping into somebody, but if you try to run from one side of the room to the other, chances are you will collide with a few people along the way.

When gas molecules collide with their container, we can measure the force per unit area of these collisions. We refer to this measurement as the pressure of the gas. When collisions increase, the overall pressure increases.

This means that as temperature rises, gas particles move more quickly, which in turn causes them to have more collisions with their container. We register this increase in collisions as pressure. Thus, we observe an increased pressure with an increased temperature, thereby confirming Gay-Lussac's Law.