What will cause the gas pressure inside a container to decrease?

2 Answers
Apr 6, 2017

A decrease in temperature inside the container.


Guy Lusacc's law gives the relationship between temperature and Pressure.

# P_1/T_1 = P_2/T_2#

This gas law says that pressure and temperature are directly related ( in terms of K^o degrees Kelvin. ) If the temperature decreases the pressure will also decrease.

Temperature is a measure of kinetic energy. When the temperature inside the container decreases the kinetic energy will also decrease.
This means that the molecules inside the container will slow down and have less energy. With less energy the molecules will hit with less force creating less pressure

Pressure can decrease if the number of molecules decreases, the temperature decreases, or a combination of these occurs.


I will assume that the gas follows the ideal gas law.

The ideal gas law states that


where #P# is the pressure, #V# is the volume, #n# is the number of molecules, #R# is a constant, and #T# is temperature.

If the container is flexible, nothing will decrease the pressure, because the container will adjust its volume to keep the pressure constant.

Thus, the container must be rigid (#V# is constant).

In order for #P# to decrease, either #n# decreases or #T# decreases or a combination of these occurs.