0.718* 10^-1 V volt is the potential difference required.
Explanation:
From the formula, W (input) =q( charge on the ion) *Potential difference
Work input in the form of energy is given = 1.15X10^-20 J
since Na^+ is positively charged with +1 so charge on it will be
1.6X10^-19 C
so,
Potential difference= work input/charge on the sodium ion
= 1.15*10^-20 / 1.6*10^-19
= 0.718* 10^-1 V
Potential difference required between the inner and outer surfaces of the cell is 0.718 *10^-1