(1) According to this law, “Equal volumes of any two gases at the same temperature and pressure contain the same number of molecules.”
Thus, V∝ n (at constant T and P)
or V = Kn (where K is constant)
(2) One mole of any gas contains the same number of molecules (Avogadro's number =6.02×1023) and by this law must occupy the same volume at a given temperature and pressure. The volume of one mole of a gas is called molar volume, Vm which is 22.4 L mol-1 at S.T.P. or N.T.P.
(3) This law can also express as, “The molar gas volume at a given temperature and pressure is a specific constant independent of the nature of the gas”.
Thus, Vm = specific constant = 22.4 Lmol-1 at S.T.P. or N.T.P.