Cell reactiomn is spontaneous when

Options

A. `E_("red")^(@)` is negative
B. `E_("red")^(@)` is positive
C. `DeltaG^(@)` is negative
D. `DeltaG^(@)` is positive

Answer

C

Explanation

If the standard emf of the cell is `E` and `nF` is the amount of charge passed and `Delta_(r)G^(@)` is the standard Gibbs energy of the reaction, then
`Delta_(r)G^(@) = -nFE_("cell")^(@)`
For a reaction to be spontaneous, `Delta_(r)G^(@)` should be negative while `E_("cell")^(@)` should be positive.