1. Chapter 14.1 Properties of Gases
Chemistry

2. Compressibility
Remember a gas will expand to fill its container. Gases are also easily compressed or squeezed into a smaller volume.
Compressibility is the measure of how much the volume of matter decreases under pressure.
Gases are easily compressed because of the space between the particles in a gas. The volume of the particles of a gas is small compared to the overall volume of the gas. There can be a large distance between particles in a gas, but under pressure the gas particles are forced together.

4. Factors Affecting Gas Pressure
Gas particles will move in straight lines until they collide with other particles or wall of the container. The motion of particles is constant and random. Gas particles move freely.
There are four variables that usually describe a gas. They are:
Pressure (P) in kilopascals
Volume (V) in liters
Temperature (T) in kelvins
Number of moles (n)

5. Amount of Gas
If you add more gas to a closed container the pressure increases. Collision between the particles and the wall of the container happen more frequently increasing pressure.
In a rigid closed container the volume is constant. We also do not change the temperature. If we double the amount of gas particles in the container then we double the pressure. If we add gas particles the pressure will increase until the container bursts.
Removing a gas from a rigid, enclosed container has the opposite effect. It will decrease the pressure.

7. If the pressure inside a sealed container is lower than outside air pressure, air will rush into the container. Gas will move from an area of high pressure to an area of low pressure. This is how an aerosol can works. There is less pressure inside the can and when you push the button it exposes the inside pressure to the outside air pressure.

8. Volume
If you reduce the volume of a container that increases the pressure. The more a gas is compressed the greater the pressure will be. If we decrease the volume that will speed up the particles and increase pressure.
If you increase the volume, the pressure decreases.

9. Temperature
An increase in temperature of an enclosed gas will increase pressure. As a gas is heated, the particles move faster. This will cause the particles to strike the walls of their container with more energy.
If temperature is decreased the pressure will decrease. The particles will slow down.