Chapter 20, Problem 62A

(a)

Interpretation Introduction

Interpretation:The growing electrode is to be mentioned with reaction.

Concept Introduction: The cathode is the negative terminal of the cell in which positive ions get reduced.

Answer to Problem 62A

The Zn electrode (cathode) grows due to the following reaction:

  ${\text{Cu}}^{2+}+2e^{-}\to \text{Cu}$ (deposit at cathode)

Explanation of Solution

In the electrolytic cell reaction, the copper ions present in the solution get reduced at the cathode and copper metal gets deposited on the cathode, therefore, its size increases.

(b)

Interpretation Introduction

Interpretation:The reducing electrode is to be mentioned with reaction.

Concept Introduction: The anode is the positive terminal of the cell in which negative ions or uncharged metals get oxidized.

Answer to Problem 62A

The Cu electrode (anode) reduces due to the following reaction:

  ${\text{Cu}}^{2+}+2e^{-}\to \text{Cu}$ (anode dissolves)

Explanation of Solution

In the electrolytic cell reaction, the copper ions present in the solution get reduced at the cathode and the copper electrode gets oxidized to ${\text{Cu}}^{2+}$ to maintain the concentration of electrolyte and flow of current, therefore, gets reduced.