The Edison storage cell is represented as
`Fe(s) | FeO (s)| KOH(aq) | Ni_2O_3(s)|Ni(s)`.
The half cell reactions ar
`NiO_3 (s) + H_2O(l) + 2e = 2NiO(s) + 2OH^(-) " " E^@ = +0.40V`
`FeO(s) + H_2O(l) +2e = Fe(s) + 2OH^(-)" " E^@ = -0.87V`
(i) What is the cell reaction? (ii) What is the cell emf? How does it depend on the concentration of KOH? (iii) What is the maximum amount of electrical energy that can be obtained from one mole of `Ni_2O_3` ?

Explanation

Electrical energy = nFE
`(i) Ni_2O_3(s) + Fe(s) to 2NiO(s) + FeO(s)`
(ii) 1.27V, Independent of [KOH]
(iii) 245.11kJ/mole of `Ni_2O_3`