Question

Name the processes from which chlorine is obtained as a by-product. What

will happen if an aqueous solution of NaCl is subjected to electrolysis?

Answer 1

In the electrolysis of molten NaCl, Cl₂ is obtained at the anode as a by product.

At cathode:

At anode:

The overall reaction is as follows:

If an aqueous solution of NaCl is electrolyzed, Cl₂ will be obtained at the anode but at the cathode, H₂ will be obtained (instead of Na). This is because the standard reduction potential of Na (E°= − 2.71 V) is more negative than that of H₂O (E° = − 0.83 V). Hence, H₂O will get preference to get reduced at the cathode and as a result, H₂ is evolved.

At cathode:

At anode: