Question

To the Daniel cell, if $ZnS{O}_4$ is added to the left hand side electrode, then cell emf:

• A. increases
• B. decreases
• C. does not change
• D. first increases & then decreses

Answer 1

The correct option is B decreases

The reduction potential of anode is directly proportional to the concentration of the electrolyte. When zinc sulphate is added to the solution present in the anode compartment, then the concentration of the solution increases. This increases the reduction potential of anode.

Hence, the emf of the cell decreases as $E_{cell}=E_{cathode}-E_{anode}$.

Hence, option $B$ is correct.