Chapter 19, Problem 19.97SP

Interpretation Introduction

Interpretation:

The concentration of ${\text{Cu}}^{\text{2+}}$ in $\text{CuSO}$ solution needs to be determined if the measured cell potential at 25°C is 0.67 V and the galvanic cell has an iron electrode in contact with 0.10 M $\text{FeSO}$ and a copper electrode in contact with $\text{CuSO}$ solution.

Concept introduction:

In the electrochemical cell, the reactions at cathode and anode occur due to the difference in their reduction electrode potential value. The EMF of the cell can be calculated with the help of electrode reduction potential values. The reaction at each electrode is called as half-reaction and the combination of both half-reactions gives the cell reaction of given electrochemical cell. The standard cell potential for an electrochemical cell can be calculated as:

$\begin{array}{l}{\text{E}}_{\text{cell}}^{\text{°}}{\text{ = E}}_{\text{cathode}}^{\text{°}}\text{}{\text{ - E}}_{\text{anode}}^{\text{°}}\\ {\text{E}}_{\text{cell}}^{\text{°}}{\text{ = E}}_{\text{reduction}}^{\text{°}}\text{}{\text{ - E}}_{\text{oxidation}}^{\text{°}}\end{array}$

The potential of a cell can be calculated with the help of the Nernst equation that can be shown as:

$\begin{array}{l}{\text{E° = E°}}_{\text{cell}}\text{ - }\frac{\text{0}\text{.0592 V}}{\text{n}}\text{ log Q }\\ \text{n = number of electrons}\\ \text{Q = reaction quotient}\end{array}$