Question

A galvanic cell is constructed with a silver-silver chloride electrode, and a nickel strip immersed in a beaker containing 3.01 x 10^-2 M solution of NiCl₂. Determine the balanced cell reaction and calculate the potential of the cell. Enter in volts. (assume a temperature of 25

Answer 1

The half cell reaction for Ag/AgCl

AgCl (s) + e^- -----------> Ag (aq) + Cl^- (aq) ; E_red⁰ = 0.228 V

Half cell reaction for Ni²⁺/ Ni is -

Ni²⁺ (aq) + 2 e^- ------> Ni (s); E_red⁰ = -0.250 V

Hence -

From the above two equations, the net cell reaction is -

2 AgCl (s) + Ni (s) ---------> Ni²⁺ (aq) (3.01*10^-2 M) + 2 Ag (s)

Therefore -

E⁰_cell = E⁰(red) + E⁰(oxi)

        = 0.228 + 0.250 = +0.478 V

Therefore -

E_cell (non standard conditions) = E⁰ - (0.0592/2) log [Ni²⁺]

                                             = 0.478 - (0.0592/2) log (3.01 x 10^-2 )

                                             = 0.523 V