Explain clearly how the phenomenon of adsorption finds applications in
(i) production of vacuum in a vessel
(ii) heterogeneous cataysis
(iii) Froth floatation process in metallurgy

Explanation

(i) Proudction of vacuum : The adsorption of air in liquid air helps to create a high vaccum in a vessel. This process is used in high vaccum instruments as Dewar flask for storage of liquid air or liquid hydrogen. The remaining traces of air can be adsorbed by charcoal from the vessel evacuated by a vaccum pump to give a very high vaccum.
(ii) Heterogeneous catalysis : The phenomenon of adsorption is useful in the heterogeneous catalysis Adsorption of reactants on the solid surface of catalysts increases the rate of · reaction. The metals such as Fe, Ni, Pt, Pd, etc. are used in the manufacturing process.
(iii) Froth Floatation process : When sulphide one is shaken with pine oil and water t~e ore particles are adrorbed on the froth that floats and the gangue particles settle down m the tank.