Question

The first step in producing pure lead from galena $(PbS)$ is as follows: $ 2{PbS}(s) + 3{O}_2(g) \longrightarrow 2{PbO}(s) + 2{SO}_2(g) $. 
All of the following are true concerning this reaction except:

• A. Both lead and sulphur are oxidised
• B. Oxygen is the oxidising agent
• C. Lead sulphide is the reducing agent
• D. Lead is neither oxidised nor reduced

Hint:

When oxygen is involved, it typically acts as the oxidising agent, and the element that gains electrons is reduced.

Answer 1

The Correct Option is A

In the reaction, lead in PbS is reduced from +2 to 0, meaning that it gains electrons, which is the characteristic of a reduction process. Similarly, oxygen is reduced as it gains electrons, while sulphur in PbS is oxidized, as it loses electrons (its oxidation state increases from -2 to 0). Therefore, the statement that both lead and sulphur are oxidized is false because, in fact, lead is reduced, not oxidized.

Thus, the correct interpretation is that lead is reduced and sulphur is oxidized in this reaction.