The purpose of this lab is to determine how pressure, temperature, and volume are related in a gas. Gases can be easily compressed because they have relatively large distances between the atoms or molecules as they bounce back and forth in the walls of the container they occupy. When the volume of the container that the gas occupies is changed, the distance between the sides changes and the amount of time it takes for a particle to get from one side to the other changes. The number of collisions per second changes which results in a change in pressure. Decreasing the volume the gas occupies, decreases the pressure. This was discovered by Robert Boyle. Boyle's law states that the volume of a fixed quantity of gas at a constant temperature is inversely proportional to the pressure. Joseph Gay-Lussac discovered that if gas is allowed to expand, increasing the temperature will force the gas to expand while maintaining constant pressure. If the gas is not allowed to expand, the increase in kinetic energy from the increase in temperature will increase the pressure.
To determine the relationship between pressure and volume an experiment will be performed at a constant temperature. Then an experiment will be conducted at a constant volume to determine the relationship between pressure and temperature.