Chapter 19, Problem 19.132SP

Interpretation Introduction

(a)

Interpretation:

The sketch of the cell should be drawn that shows the anode and cathode, the sign of the electrodes and the direction of electrons and ion flow for the electrolysis of molten magnesium chloride using inter electrode to produce magnesium metal.

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 help of electrode reduction potential values. The reaction at each electrode is called as half-reaction and combination of both half-reaction 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 cell can be calculated with the help of Nernst equation that can be shown as:

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

Interpretation Introduction

(b)

Interpretation:

The balance equation for anode, cathode and overall cell reaction for the electrolysis of molten magnesium chloride using inter electrode to produce magnesium metal should be determined.

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 help of electrode reduction potential values. The reaction at each electrode is called as half-reaction and combination of both half-reaction 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 cell can be calculated with the help of Nernst equation that can be shown as:

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