(a) Differentiate between the following: (i) Adsorption and Absorption (ii) Lyophobic Sol and Lyophilic Sol (iii) Multimolecular Colloid and Macromolecular colloid. OR (b) (I) Define the following terms: (i) Zeta Potential (ii) Coagulation (II) Why a negatively charged sol is obtained when $\mathrm{AgNO}_3$ solution is added to $\mathrm{KI}$ solution?