# Charles' Law !

**An animation of an experiment demonstrating Charles' Law. A volume of gas is heated and the volume and temperature recorded in a table. **

**An animation plotting a graph of volume against temperature to illustrate Charles' Law. The results from Charles' Law are presented in a table. Plotting the results in a volume-temperature graph.**

**An animation illustrating the volume-temperature graph for a gas. The units on the temperature scale of the graph from Charles' Law 2 are converted from Celsius to Kelvin and the graph extrapolated to absolute zero. **

**Charles's law** (also known as the **law** of volumes) is an experimental gas **law** that describes how gases tend to expand when heated. A modern statement of**Charles's law** is: When the pressure on a sample of a dry gas is held constant, the Kelvin temperature and the volume will be directly related.

Also known as the **law** of volumes, **Charles's Law** is an experimental gas **law** which describes how gases tend to expand when heated. It was first published by French natural philosopher Joseph Louis Gay-Lussac in 1802, although he credited the**discovery** to unpublished work from the 1780s by Jacques **Charles**, hence the name.

For a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional. Or **Boyle's law** is a gas **law**, stating that the pressure and volume of a gas have an inverse relationship, when temperature is held constant.

If the **volume** of a container is decreased, the **temperature** decreases. Suppose the**temperature** is **increased**. This means gas molecules will move faster and they will impact the container walls more often. This means the gas pressure inside the container will **increase** (but only for an instant.

Charles' law states: "For a fixed mass of **gas**, at a constant pressure, the **volume** (V) is directly proportional to the absolute **temperature** (T)." ... If the internal pressure increases the piston will move up to allow the pressure to equalise.

Charles' Law: The Temperature-Volume Law. This law states that the volume of a given amount of gas held at constant pressure is directly **proportional** to the Kelvin temperature. As the volume goes up, the temperature also goes up, and vice-versa.

**Pressure and volume** are inversely proportional to each other. This means that as the **pressure** decreases, the **volume** increases, and as the **pressure** increases, the**volume** decreases. One way to think of this is if you push on a **gas** by decreasing its**volume**, it pushes back by increasing its **pressure**.

One way to think of this is if you increase the speed of the molecules –by increasing their temperature- the force of the molecules hitting their container increases and this increases the pressure. This relationship is called **Gay-Lussac's Law** and makes up part of the **ideal gas law**.