Chapter 21, Problem 74A

Interpretation Introduction

Interpretation: In a voltaic cell, an anode (produces electrons) is considered negative but in most cases, the anode is considered a positively charged electrode. The reason for this needs to be explained.

Concept Introduction: In electrochemistry, the relationship between electrical potential differences and potential differences due to chemical change is explained. The two types of cells that can be studied in electrochemistry are electrolytic cells and voltaic cells.

Explanation of Solution

In all types of electrochemical cells, oxidation occurs at the anode and reduction takes place at the cathode. In the case of a voltaic cell, the anode has a negative reduction potential (as oxidation occurs) and the cathode has a positive reduction potential (as reduction occurs). Due to this reason, the anode is considered negative. In the case of an electrolytic cell, the anode is connected to the positive terminal of the battery; thus, it acts as positive.