Extraction of Metals - Result Question 75

Answer:

Correct Answer: 78. (2)

Solution:

78. The reactions involved in the extraction of lead from galena $(PbS)$ by self reduction are

$ \begin{aligned} 2 PbS+3 O _2 & \longrightarrow 2 PbO+2 SO _2 \\ PbS+2 PbO & \longrightarrow 3 Pb+SO _2 \\ PbS+2 O _2 & \longrightarrow PbSO _4 \text { (side reaction) } \\ PbSO _4+PbS & \longrightarrow 2 Pb+2 SO _2 \end{aligned} $

In litharge $(PbO)$, the oxidation state of $Pb$ is +2