Among the following, the applications of Graham's law are    a) In Marsh gas alarm            b) In designing eudiometer            c) In separating uranium isotopes        d) To measure volume of a gas by gas burette

Marsh gas(methane) alarm is a saftey device used by miners to detect leakage of poisonous gases.Molar mass of methane is lesser than oxygen and nitrogen,its rate of diffusion is faster.Seperation of Uranium isotopes principle of diffusion is employed.This is known as enrichment.Mixture of U238 and U235 are present in natural sample which converted to gaseous hexafluorides.UF6  238  and UF6  235  differ in rate of diffusion ; rUF6  235 rUF6  238 =353349 ;