Chapter 17.1, Problem 2TY

Interpretation Introduction

Interpretation:

The voltage required to complete the electrolysis ${\text{I}}^{\text{-}}{\text{ to I}}_{\text{3}}{}^{\text{-}}$ has to be calculated.

Concept Introduction:

When the electric current is too small, the voltage of cell is given as

$\text{E = E(cathode)}\text{-}\text{E(anode)}$

E(cathode) is electrode’s potential which is attached to negative terminal of current source.

E(anode) is electrode’s potential which is attached to positive  terminal of current source.

Overpotential: The activation energy of a reaction at an electrode can be overcome by voltage.  The required voltage to apply is called overpotential.

Ohmic potential:  In electrochemical cell, the electrical resistance of a solution while current I flows can be overcome by voltage.  The required voltage to apply is called ohmic potential.

${\text{E}}_{\text{ohmic}}\text{=}\text{IR}$

Concentration Polarization:  It is the change in concentration of products and reactants at electrode’s surface unlike they are same in solution.