Out of C and CO, which is a better reducing agent for ZnO ?
The value of △fG∘ should be negative, for a reaction to occur,
I. reaction ZnO+C⟶Zn+CO△fG∘ becomes lesser as the T is more than 1120 K.
II. reaction ZnO+CO⟶Zn+CO2△fG∘become lesser when T is more than 1323 K.
For I equation, at a lower temperature, △G∘ becomes negative. So, the I reaction is feasible i.e., C is a better reducing agent for ZnO but not CO.