Class 12 NEET Chemistry Electrochemistry Questions

C5H12(g)+O2(g)→5CO2(g)+6H2O(l)
ΔG°=[(−394.4×5)+(−237.2×6)]−[(−8.2)+(8×0)]
=−3387 kJ
Note that the standard free energy change of elementary substances is taken as zero.
For the fuel cell, the complete cell reaction is :
C5H12(g)+8O2(g)→5CO2(g)+6H2O(l)
Which is the combination of the following two half reactions:
C5H12(g)+10H2O(l)→5CO2(g)+32H++32eand
8O2(g)+32H++32e→16H2O(l)
Therefore, the number of electrons exchanged is 32 here, means n = 32. This is the trickiest part of the problem.
ΔG°=nFE°
−3387×103J=−32×96500

J

Volt

×E°
Then E°=1.0968V