Question

When a dilute aqueous solution of $NaCl$is electrolyzed between platinum electrodes, hydrogen gas is evolved at the cathode but metal sodium is not deposited. Give reason.

Answer 1

• Electrolysis is the process of breaking a compound in its molten or aqueous form by passing electricity through it.
• In the activity series, Hydrogen$\left(H\right)$ is much below Sodium$\left(Na\right)$, therefore Hydrogen is discharged at the cathode in preference to Sodium.
• Also, the concentration of Sodium Chloride $\left(NaCl\right)$is less due to which it prefers the discharge of Hydrogen.

Therefore, Hydrogen is evolved at the cathode during the electrolysis of Sodium Chloride ($NaCl$)as Hydrogen is below in the activity series than Sodium, and also the concentration of Sodium Chloride ($NaCl$)is less due to which it prefers the discharge of Hydrogen.