Most Important Selected Qs for JEE AdvancedChemistryElectrochemistry
Consider the following solutions Solution P : aq. solution of Cu ( NO ₃ )₂ Solution Q : aq. solution of AgNO ₃ Solution R : conc. aq. solution of NaCl Solution S : aq. solution of KNO ₃ If electrolysis of these solutions takes place using inert electrodes, in different containers. Among the following, set of the solution(s) in which pH does not increase due to electrolysis is/are (assume no volume change due to elect
Options
- AP and Q
- BR
- CS
- DP and S -
Correct answer
D. P and S -
Step-by-step solution
Hint : If more H ⁺ is formed pH decreases, but if more OH ⁻ is formed pH increases. Solution : Electrolysis (P) Cathode Cu ²⁺+2 e ⁻ Cu ( ~s ) Anode H ₂ O 1 2 O ₂+2 H ⁺+2 e ⁻ pH (Q) Cathode Ag ⁺+1 e ⁻ Ag ( ~s ) Anode H ₂ O 1 2 O ₂+2 H ⁺+2 e ⁻ pH (R) Cathode 2 H ₂ O +2 e ⁻ H ₂+2 OH ⁻ Anode aligned & Cl ⁻ 1 2 Cl ₂+1 e ⁻ & pH aligned (S) Cathode 2 H ₂ O +2 e ⁻ H ₂+2 OH ⁻ Anode H ₂ O 1 2 O ₂+2 H ⁺+2 e ⁻