For the feasibility of a redox reaction in a cell, the emf should be.

Options

A. Fixed
B. positive
C. Zero
D. Negative

Answer

B

Explanation

Any redox reaction would occur spontaneously if the free energy charnge `(Delta G)` is negative.
`Delta G^@ = nFE^2`
Where n is the number of electrons involved, F is the value of faraday and `E^@` is the cell emf. `Delta G^2` can be negative if `E^2` is positive.