Question

Cell reaction is spontaneous when

• A. $E^0_{red} $ is negative
• B. $E^0_{red} $ is positive
• C. $\Delta G^0 $ is negative
• D. $\Delta G^0 $ is positive

Answer 1

Answer: (C)

When the value of $\Delta G^0 $ is negative, the cell reaction is spontaneous.
$\, \, \, \, \, \, \, \, \, \, \, \, \Delta G^0=-nFE^0 $
where, n = number of electrons take part
F = Faraday constant $E^0= $ EMF of the cell
Thus, for a spontaneous reaction, the EMF of the cell must be positive.