Chemistry - Surface Chemistry Question with Solution | TestHub

Statement A is correct because for spontaneous adsorption ($\Delta G<0$), where entropy decreases ($\Delta S<0$), the process must be exothermic ($\Delta H<0$) to satisfy the Gibbs free energy equation:

$$\Delta G=\Delta H-T\Delta S$$

Statement C is correct as ferric hydroxide sol, prepared by hydrolysis, is positively charged and thus migrates toward the negative electrode (cathode) during electrophoresis.

Statement B is incorrect because micelle formation occurs above the Kraft temperature ($T_k$), and Statement D is incorrect because higher-valency ions have lower coagulation values.