Give reason for the following :
(a) Rough surface of catalyst is more effective than smooth surface.
(b) Smoke is passed through charged surface before allowing it to come out of chimneys in factories.
(c) Ne gets more easily adsorbed over charcoal than He.

Explanation

(a) Rough surface of the catalyst being u neven provides more surface are for adsorption as compared to smooth surface in heterogeneous catalysis.
(b) Smoke consist of colloidal particles (unburnt carbon and poisonous gases). When these come in contact with the smoke coming out of the factory is free from pollutans.
(c ) The atomic size of Ne is more than the of He. As a result, the van der Waals' forces of attraction in Ne are stronger and it gets more easily adsorbed on the surface of charcoal as compared to He.