A galvanic cell has $E_{cell}^{\circ} = 0.50 V$ and the cell reaction involves 3 electrons. Taking $F = 96500 C mo l^{- 1}$ , $Δ_{r} G^{\circ}$ of the cell reaction is

Answer: A

Δ_{r} G^{\circ} = - n F E_{cell}^{\circ} = - 3 \times 96500 \times 0.50 = - 144750 J mo l^{- 1} = - 144.75 kJ mo l^{- 1}

. A positive EMF corresponds to a negative Gibbs energy change (spontaneous). Option B forgets the factor

n

; option D has wrong units.