Question
Consider the cell Zn/Zn2+ (aq) (1.0 M) || Cu2+ (aq) (0.1 M) | Cu The standard reaction potentials are + 0.35 V for 2e– + Cu2+ (aq) → Cu and – 0.763 V for 2e– + Zn2+ (aq) → Zn
(i) Write down the cell reaction.
(ii) Calculate the emf of the cell.
(iii) Is the cell reaction spontaneous or not?
Solution
(I)Cell Reaction:
Oxidation: Zn----> Zn2+ +2e-
Reduction: Cu2+ +2e------> Cu
Therefore overall reaction
Zn +Cu2+ ------> Zn2+ +Cu
(ii) =+0.35-(-0.763)
=1.113 volts
(iii) Since EMF of cell is positive, it is a spontaneous reaction.
