# Question #4f1f4

##### 1 Answer

#### Explanation:

**Charles' Law** states that when the pressure and the number of moles of gas present in a sample are **kept constant**, the volume of the gas and its temperature have a **direct relationship**.

This means that under these conditions, if you **increase** the temperature of the gas, its volume will **increase** as well. Similarly, if you **decrease** the temperature of the gas, its volume will **decrease** as well.

So, if you take

#V_1/T_1 = V_2/T_2 -># Charles' LawKeep in mind that this equation uses the temperature of the gas expressed in

Kelvin!

So, for example, you can rearrange the equation to see how a change in temperature would affect the volume of the gas.

#V_2 = T_2/T_1 * V_1#

Notice that if the temperature of the gas **increases**

#T_2 > T_1#

then its volume will **increase** as well because

#V_2 = overbrace(T_2/T_1)^(color(blue)(>1)) * V_1 implies V_2 > V_1#

This is the case because when you increase the temperature of a gas, you increase the **kinetic energy** of its molecules. When that happens, the force and frequency with which these molecules hit the walls of the container increase.

When the pressure is *kept constant*, this increase in how hard and frequent the molecules hit the walls of the container causes the volume of the container to **expand**.