Boyle's Law & Charles Law Related

People often ask about how Boyles Law and Charles Law are related. Boyle's Law and Charles Law can be combined in a general gas equation. The equation that relates Boyle's Law and Charles Law is given below.

What is the equation linking Boyles Law and Charles Law used for?

The equation linking Charles Law and Boyles Law is useful for correcting the volume of a fixed mass of gas under one set of conditions of temperature and pressure to the volume of gas under a different set of conditions.

If a gas is at 0 degree Celsius and 101.3 k Pa, then the condition is called Standard Temperature and Pressure or stp.

Example of problem using relationship between Boyle's Law & Charles Law

A fixed mass of gas has a volume of 76cm3 at 27 degree Celsius and 100 k Pa pressure. Find the volume that the gas would have at stp.

V1 = volume before correction = 76 cm3	V2 = volume after correction - unknown
P1 = pressure before correction = 100kPa	P2 = pressure after correction = 101.3kPa
T1 = temperature before correction = 300K	T2 = temperature after correction = 273K

Using the relationship between Boyle's Law and Charles Law above, substitute all numbers. We then have:

Since both the pressure has increased and the temperature has decreased, it is expected that the answer would be less than 76 cm³. And, it is.