Question

the measured emf at 25°C for the cell reaction. Zn + Cu2+(1.0M) gives Cu + Zn 2+(0.1M) is 1.3 volt calculate E° for the cell​

Answer 1

Given :

Emf of cell reaction (E) = 1.3 V

To find :

E° for the cell =?

Solution:

• By using Nernst equation

        Ecell = E°cell - (0.0591/2)×log(I zn²⁺ I / I cu²⁺ I)

• By substituting the values in above equation

•  1.3 = E°cell - (0.0591/2)×log( 0.1/1)

•  1.3  = E°cell +0.02955×log(10)

•  E°cell = 1.3 - 0.2955

•  E°cell =  1.27 V

E° for the cell is 1.27V