Question

Why is Zinc not extracted from zinc oxide through reduction using CO?

Answer 1

Hey there....

2Zn + O2 → 2ZnO , ∆G° = -650kJ ......(1)

2CO + O2 → 2CO2 , ∆G° = -450kJ.......(2)

From equations (1) & (2) :


2ZnO + 2CO → 2Zn + 2CO2 , ∆G° = +200kJ

Therefore,

ZnO + CO → Zn + CO2 ; ∆G° = +100kJ

Since ∆G° is positive; therefore reduction will not take place.

Hope it helps...✌

Answer 2

Value of ΔG in the formation of ZnO from Zn is aprox -650 KJ/mol

While value of ΔG in the formation of CO2 from CO is aprox -450 KJ/mol

So, CO cant reduce ZnO to Zn because the gibbs free energy in the conversion of ZnO from Zn is much lower