Avogadro's Law states that the volume of any gas is proportional to the number of mole molecules of the gas. Calling, n the number of moles of molecules of the gas, the proportionality equation is: V is proportional to n => V = K*n. The proportionality constant depends on the temperature and pressure. K = (RT / P) => V = (RT/P) * n, So, Avogadro's law states that <span>at constant pressure and temperature, the volume of a gas is directly proportional to the number of moles of molecules of the gas.</span>