Answer: 45 kJ
2Fe3+(aq)+2I–(aq)→2Fe+2(aq)+I2(s)
ΔG0=−nFE0
Fe3+(aq)+e−→Fe2+(aq)....(1); ΔG01=−1FE0
Fe2+(aq)+2e−→Fe(s)......(2); ΔG02=+2F×0.44
Adding equation (1) and (2), we get,
Fe3+(aq)+3e−→Fe(s).......(3); ΔG03=−3FE0
Thus,
ΔG03=ΔG01+ΔG02
−3F×−0.036=−1FE0+2F×0.44
−E0Fe+3/Fe+2=3×(0.036)−2×(0.44)
E0Fe+3/Fe+2=−3×(0.036)+2×(0.44)
=–0.108+0.88
=0.772 V
E0 of the given reaction is
Eocell=EoFe+3/Fe+2+EoI−/I2
=0.772–0.539=0.233V
ΔG°=−nFE0cell
=−2×96500×0.233
=−44969 J=−44.9 kJ≃−45 kJ
Thus, answer is 45