Gas Laws

A series of free High School Chemistry Video Lessons.

In this lesson, we will learn

  • Boyle's Law
  • Charles' Law
  • Gay-Lussac’s Law
  • Combined Gas Law
  • Ideal Gas Law

Boyle's Law

Boyle’s Law states that volume of a given amount of gas held at a constant temperature varies inversely the with pressure. The relationship between pressure and volume of Boyle’s Law is expressed in mathematical terms as P1V1= P2V2.

An introduction to the relationship between pressure and volume, and an explanation of how to solve gas problems with Boyle's Law

Understanding and applying Boyle's Law


Charles' Law

Charles' Law states that the volume of a given mass of a gas is directly proportional to its Kevin temperature at constant pressure. In mathematical terms, the relationship between temperature and volume is expressed as V1/T1=V2/T2.

Discusses the relationship between volume and temperature of a gas, and explains how to solve problems using Charles' Law

Understanding and applying Charles' Law.


Gay-Lussac’s Law

Gay-Lussac’s Law states that the pressure of a given mass of gas varies directly with the Kelvin temperature when the volume remains constant. Gay-Lussac’s Law is expressed in a formula form as P1/T1 = P2/T2. When dealing with Gay-Lussac’s Law, the unit of the temperature should always be in Kelvin.

Using Gay-Lussac's Law to understand the relationship between a gas' pressure and temperature.

A bunch of example problems that show how to use Gay-Lussac's Law.


A bunch of example problems that show how to use Gay-Lussac's Law.

Combined Gas Law

The Combined Gas Law combines Charles’ Law, Boyle’s Law and Gay Lussac’s Law. The Combined Gas Law states that a gas’ (pressure × volume) / temperature = constant.

The combined law for gases.

Discusses how to solve problems with the Combined Gas Equation.

Ideal Gas Law

The Ideal Gas Law mathematically relates the pressure, volume, amount and temperature of a gas with the equation pressure × volume = moles × ideal gas constant × temperature; PV = nRT. The Ideal Gas Law is ideal because it ignores interactions between the gas particles in order to simplify the equation. There is also a Real Gas Law which is much more complicated and produces a result which, under most circumstances, is almost identical to that predicted by the Ideal Gas Law.

Understanding and applying the ideal gas law.


Sample problems for using the Ideal Gas Law, PV=nRT



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