Q. Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?
A) The ΔG°f of the sulphide is greater than those for CS₂ and H₂S.
B) The ΔG°f is negative for roasting of sulphide ore to oxide.
C) Roasting of the sulphide to the oxide is thermodynamically feasible.
D) Carbon and hydrogen are suitable reducing agents for metal sulphides.
Explanation
[Solution from source] Metal sulphides have ΔG°f lower than CS₂ and H₂S, so carbon and hydrogen cannot reduce them; that is why sulphides are roasted to oxides first. The statement that C and H₂ are suitable reducing agents for sulphides is therefore the untrue one. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.