Explain how the phenomenon of adsorption finds application in each of the following processes:
(i) Production of vacuum
(ii) Heterogeneous catalysis
(iii)Froth Floatation process
i) Production of high vacuum: Traces of air can be adsorbed by charcoal from a vessel, evacuated by a vacuum pump to give a very high vacuum.
(ii) Heterogeneous catalysis: heterogeneous catalysis refers to the form of catalysis where the phase of the catalyst differs from that of the reactants. Phase here refers not only to solid, liquid, or gas, but also immiscible liquids, e.g. oil and water
For example: N2(g) + 3H2(g) 
2NH3(g)
(iii) Froth floatation process: This process is used to remove gangue from sulphide ores. The basic principle involved in this process is adsorption. In this process, a mixture of water and pine oil is taken in the tank. The impure powdered sulphide ore is dropped in through hopper and the compressed air is blown in through the agitator. The agitator is rotated several times. As a result, the froth is formed and the sulphide ores get adsorbed in the froth. The impurities settled down and are let out through an outlet at the bottom. The froth formed is collected in froth collector tank. After sometime, the ore particles in the froth collecting tank start settling gradually, which are then used for further metallurgical operations.
