The choice of a reducing agent in a particular case depends on thermodynamic factor. How far do you agree with this statement ? Support your opinion with example.

Explanation

Thermodynamic factors have a major role in selecting the reducing agent for a particular reaction.
(i) Only that reagent will be preferred which will lead to decrease in free energy `(DeltaG^(@))` at a certain specific temperature.
(ii) A metal oxide placed lower in the Ellingham diagram cannot be reduced by the metal involved in the formation of the oxide placed higher in the diagram.
Examples :
(i) `Al_(2)O_(3)` cannot be reduced by Cr present in `Cr_(2)O_(3)` since the curve for `Al_(2)O_(3)` is placed below that of `Cr_(2)O_(3)` in the Ellingham diagram
(ii) CO cannot reduce ZnO because there is hardly any change in free energy `(DeltaG^(@))` as a result of the reaction.