Chapter 21, Problem 81A

Interpretation Introduction

Interpretation: If an engineer has proposed a new battery design where silver is used as an electrode in both half-cells, what should a chemist tell about the proposal needs to be explained.

Concept Introduction: In an electrochemical process, a redox reaction takes place. Here, two half-reactions occur where in one reaction oxidation takes place and in the other reaction, reduction takes place. The sum of these two-half reactions gives the overall reaction for the process. In oxidation, the loss of electrons takes place by an element and its oxidation state increases Similarly in reduction, the gain of electrons takes place by an element. Here, the oxidation state of the element decreases.

Explanation of Solution

In an electrochemical cell, two electrodes must be made up of two different materials. This is because two species/metals must have a different tendency to lose electrons or, there should be a difference in their standard reduction electrode potential. If two same species are used like silver in this case, both reduction and oxidation reactions will not be possible simultaneously. Thus, one cannot identify the anode and cathode in the cell or, the cell will not work.