Chapter 18, Problem 18.43QP

Interpretation Introduction

Interpretation:

Need to define overvoltage and explain the effect of overvoltage on electrolytic reaction.

Concept introduction:

In a galvanic cell the redox reaction is utilized to generate electricity, while in an electrolytic cell external voltage is applied through anode and cathode to carry out the electrochemical reaction. The potential generated by the redox reaction as well as the potential need for the electrochemical generation can be calculated by using thermodynamic parameters. But there is a difference in potential was observed between the calculated value and the experimental one, such difference is called as over potential or overvoltage. In case of galvanic cell the potential generate will be lesser than the calculated one, but in an electrolytic cell the potential needed for the electrochemical reaction will be more than the potential calculated thermodynamically.

To define: Overvoltage and explain how it affects the electrolytic process.