CBSE Class 11-science Answered

Avogadro's law tells us that at constant P and T, the volume of a gas is directly proportional to the amount of gas. Boyle's law says that volume is inversely proportional to pressure, and Charles' indicates that volume is directly proportional totemperature. These three laws may all be applied at once if we write

or, introducing a constant of proportionality R,

or we can also write PV = nRT

Equation (2) applies to all gases at low pressures and high temperatures and is a very good approximation under nearly all conditions.