Question

Give reasons : 

(i) On the basis of E^o values, O₂ gas should be liberated at anode but it is Cl₂ gas which is liberated in the electrolysis of aqueous NaCl. 

(ii) Conductivity of CH₃COOH decreases on dilution.

Answer 1

(i) NaCl → Na⁺ + Cl^-

H₂O ⇌ H⁺ + OH^-

The value of E^o of O₂ is higher than Cl₂ but O₂ is evolved from H₂O only when the higher voltage is applied. So, because of this Cl₂ is evolved instead of O₂. 

(ii) Conductivity varies with the change in the concentration of the electrolyte. The number of ions per unit volume decreases on dilution. So, conductivity decreases with decrease in concentration. Therefore, conductivity of CH₃COOH decreases on dilution.