Avogadros Law

Amadeo Avogadro was the first to propose, in 1811, a relationship between the volume of a gas and the number of molecules present in it.

It states that equal volumes of all gases at the same temperature and pressure contain equal number of molecules.

V ∝ N

At a given temperature and pressure, the number of molecules present in the gas is directly proportional to the number of moles.

N ∝ n

Therefore, V ∝ n

V/n = constant

V₁/n₁ = V₂/n₂

He also found that the number of molecules present in 1 mole of any substance (22.4 litre of any gas at 273 K temperature and 1 atmosphere pressure) is 6.022 × 10²³ molecules. This number is known as Avogadros’ number.