Question

Select the correct answer from the list in the bracket:
The anion discharged at the anode with the most difficulty. $\left({\mathrm{SO}}_4^{2-},{\mathrm{Br}}^{-},{\mathrm{NO}}_3^{-},{\mathrm{OH}}^{-}\right)$

Answer 1

• According to the electrochemical series of anions, ${\mathrm{SO}}_4^{2-}$ is the least reactive among $\left({\mathrm{SO}}_4^{2-},{\mathrm{Br}}^{-},{\mathrm{NO}}_3^{-},{\mathrm{OH}}^{-}\right)$.
  Therefore, ${\mathrm{SO}}_4^{2-}$ is discharged at anode with most difficulty.