Chapter 21, Problem 32A

Interpretation Introduction

Interpretation: The electrode in a voltaic cell where reduction always occur needs to be identified.

Concept Introduction: In an electrolytic cell, a redox reaction takes place. In a redox reaction, oxidation and reduction of species take place simultaneously. Here, oxidation occurs by loss of electron/s and reduction occurs by the gain of electron/s.

Explanation of Solution

In oxidation, the oxidation state of the species increases, and in reduction, the oxidation state of the species decreases. There are two electrodes in an electrolyte cell that is anode and cathode. At the anode, oxidation takes place and at the cathode, reduction takes place.

Thus, reduction always occurs at the cathode of an electrolyte cell.