Graham's law of diffusion

Graham's law of diffusion.

Graham's law of diffusion states that " under similar condition of temperature and pressure,the rate of diffusion is inversely proportional to square root of their densities". 

Mathematically,

 

Let r¹ r² be the rate of diffusion of gas who's densities are d¹ d² respectively. 

Then according to Graham's law of diffusion.

  

               r¹ α 1/√d¹  eq - (i) , r² α 1/√d²  eq -(ii)

Combining eq i  and and ii

We get,

                r¹/r² = √ d² / √d¹

             d¹= m¹/2 , d² = m²/2 

       

Or       

Threrefor ,