(i) Explain the meaning of the statement. ‘Adsorption is a surface phenomenon.’
(ii) State two features of chemical adsorption which are not found in physical adsorption.
(iii) Explain the terms with suitable examples: (i) Gel, (ii) Aerosol and (iii) Hydrosol.

Out of BaCl₂ and KCl, which one is more effective in causing coagulation of a negatively charged colloidal Sol? Give reason.

Give one example each of 'oil in water' and 'water in oil' emulsion.

In reference to Freundlich adsorption isotherm, write the expression for adsorption of gases on solids in the form of an equation.

Write an important characteristic of lyophilic sols.

Based on the type of particles of dispersed phase, give one example each of associated colloid and multimolecular colloid.