Question -
Answer -
Reduction of ZnO to Zn is usuallycarried out at 1673 K. From the above figure, it can be observed that above1073 K, the Gibbs free energy of formation of CO from C and above 1273 K, theGibbs free energy of formation of CO2 from C is lesser than the Gibbs free energy offormation of ZnO. Therefore, C can easily reduce ZnO to Zn.
On the other hand, the Gibbs freeenergy of formation of CO2 fromCO is always higher than the Gibbs free energy of formation of ZnO. Therefore,CO cannot reduce ZnO. Hence, C is a better reducing agent than CO for reducingZnO.