Question

In self reduction process, the species which bring about the reduction is :

• A. $O_2$
• B. $S^{2-}$
• C. $O^{2-}$
• D. $H_{2}S$

Answer 1

The correct option is B $S^{2-}$

$2PbS+3O_2\to 2PbO+2S{O}_2$
$PbS+2PbO\to 3Pb+S{O}_2$ (self reduction)
In self reduction,
$Pb\stackrel{2-}{S}+2PbO\underset{\text{Absence of air}}{\overset{\Delta }{\to }}3Pb\left(l\right)+S\stackrel{+4}{O_2}\uparrow$.