Question

Which of the following statements, about the advantage of roasting of sulphide one before reduction is not true?

• A. The $\Delta G_f^0$ of the sulphide is greater than those for $C{S}_2$ and $H_{2}S$
• B. The $\Delta G_f^0$ 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

Answer 1

Answer: (D)

Carbon and hydrogen are suitable reducing agents for metal sulphides

The correct answer is $\left(D\right)$

Carbon does not reduce metal sulphide efficiently as free energies of formation of most metal sulphides are greater than those for $C{S}_2$ and $H_{2}S$

And does not act as a good reducing agent as the entropy change in reaction of hydrogen and oxygen gas is negative.

Sulphides ores are converted to their oxides forms and then reduced to mfree metals.