Gas laws

Mechanical Engineering

Gas laws:

The laws which govern the behaviour of a perfect gas due to the variation in its pressure, temperature and volume are known as gas laws.

Three are three basic gas laws.

  1. Boyle’s law
  2. Charle’s law
  3. Gay-Lussac law

Boyle’s law: It states that when the temperature is remains constant; the volume of a perfect is inversely proportional to its absolute pressure. i.e.

V α 1/P (T is constant)

Or PV = Constant

0r P1V1 = P2V2 (when a gas changes its state from 1 to 2 at constant temperature)

Charle’s law: The volume of a perfect gas is directly proportional to its absolute temperature, if the pressure remains constant. i.e.

V α T or V/T=Constant

Or V1/T1 = V2/T2 (when a gas changes its state from 1 to 2 at constant pressure)

Gay-Lussac law: The pressure of the gas is directly proportional to its temperature if the volume remains constant. i.e.

P α T or P/T = Constant

Or P1/T1 = P2/T2 (when a gas changes its state from 1 to 2 at constant volume)