Question

The standard electrode potential of the two half cells are given below:

\[\ce{Ni^{2+} + 2e^{-} -> Ni, E_0 = - 0.25 Volt}\]

\[\ce{Zn^{2+} + 2e^{-} -> Zn, E_0 = - 0.77 Volt}\]

The voltage of cell formed by combining the two half cells would be?

Options

• –0.52 Volt

• –1.02 Volt

• +0.52 Volt

• + 1.02 Volt

Answer 1

+0.52 Volt

Explanation:

\[\ce{Ni^{2+} + 2e^{-} -> Ni, E^{o}_{red} = - 0.25 V cathode}\]

\[\ce{Zn^{2+} + 2e^{-} -> Zn, E^{o}_{red} = - 0.77 V anode}\]

\[\ce{E^{o}_{cell} = - 0.25 V - (- 0.77 V) = - 0.25 V + 0.77 V = 0.52 V}\]