Chapter 21, Problem 51A

Interpretation Introduction

Interpretation: The products of the electrolysis of molten sodium chloride need to be explained.

Concept Introduction: In an electrochemical cell, there are two electrodes; anode and cathode. At the anode, oxidation takes place and at the cathode reduction takes place.

Explanation of Solution

Sodium and chlorine can be produced through the electrolysis of pure molten sodium chloride. Here, an aqueous solution of sodium chloride is not used. Here, at the anode chloride gas is produced and molten sodium is at the cathode. The two half-reactions are represented as follows:

Oxidation-Anode:

  $2{\text{Cl}}^{-}\left(l\right)\to {\text{Cl}}_{\text{2}}\left(g\right)+2e$

Reduction-Cathode:

  $2{\text{Na}}^{+}\left(l\right)+2e\to \text{2Na}\left(l\right)$

The overall cell reaction can be represented as follows:

  $2\text{NaCl}\left(l\right)\to 2\text{Na}\left(l\right)+{\text{Cl}}_2\left(g\right)$

Thus, the products of electrolysis of molten sodium chloride are liquid sodium and chlorine gas.