Question

Choose the correct option regarding chlor-alkali process.

• A. ${\text{Cl}}_2$ is obtained at anode and ${\text{H}}_2$ is obtained at cathode.
• B. ${\text{Cl}}_2$ is obtained at cathode and ${\text{H}}_2$ is obtained at anode.
• C. Both ${\text{Cl}}_2$ and ${\text{H}}_2$ are obtained at anode.
• D. Both ${\text{Cl}}_2$ and ${\text{H}}_2$ are obtained at cathode.

Answer 1

The correct option is A ${\text{Cl}}_2$ is obtained at anode and ${\text{H}}_2$ is obtained at cathode.

When electricity is passed through brine (aqueous solution of $\text{NaCl}$), it decomposes to give sodium hydroxide, chlorine and hydrogen gas. This process is called chlor-alkali process. The reaction involved is:

$\text{2}NaCl\text{(aq)}+2H_{2}O\text{(aq)}\to \text{2}NaOH\text{(aq)}+C{l}_2\text{(g)}+H_2\text{(g)}$

Chlorine gas is given off at anode and hydrogen gas is given off at cathode.