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Illustrate with examples - (i) Lyophilic and Lyophobic sols (ii) Homogeneous and Heterogeneous catalysis. |
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Answer» SOLUTION :(i) The substances such as proteins, starch, RUBBER, etc. directly passes into the colloidal statewhen brought in contact with the solvent. Such colloids are known as lyophillic sols. The substances like metals, their sulphides, hydroxides, etc. do not form colloidal sol READILY when mixed with dispersion medium. The colloidal sols can only be PREPARED by some special methods. Such sols are called lyophobic sols. (ii) Homogeneous catalysis: Here the reactants and catalyst are present in the same phase. For example, lead chamber process for the manufacture of `H_2SO_4` . `2SO_(2)(g)+ O_2 (g) overset(NO_((g)))to 2SO_(3)(g)` Heterogeneous catalysis: Here the reactants and catalyst are present in different PHASES. For example, contact process for manufacture of `H_2SO_4` . `2SO_(2)(g) + O_(2)(g) overset(V_2O_(5(s)))to 2SO_(3)(g)` |
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