We know that gases which donot react chemically intermix irrepective of their nature. This is known as diffusion. The law of gravitation does not apply to diffusion which means that lighter gases can more downward while the hevier ones can move upwards.
(i) State Graham's Law of diffusion.
(ii)Give Its mathemartical form.
(iii) What is the value associated with the phenomenon of diffusion of gases?

Explanation

(i) According to Graham's Law of diffusion ,under similar conditions of temperature and pressure, the rates of diffusion of gases are inversely proportional to the squre roots of their densities.
(ii) Mathematically, `(r_(1))/(r_(2)) = sqrt((d_(2))/(d_(1)))`
(iii) The phenomenon of diffusion of gases is very useful in daily life. Just imagine what might have happened to the poisonous gases like oxides of nitrogen, chlorine or ammonia if released as a result of some accident in a factory. Had there been no diffusion, these gases might have got concentrated in one particular region or area. It might have gets slowly diluted and ultimately disappears.