Question
$$Pb$$ and $$Sn$$ are extracted from their chief ore by
A.
carbon reduction and self reduction.
B.
self reduction and carbon reduction.
C.
electrolysis and self reduction.
D.
self reduction and electrolysis.
Answer :
self reduction and carbon reduction.
Solution :
$$PbO\,\& \,PbS{O_4}$$ get reduced by $$PbS$$ itself which is already present in mixture so because the reduction took place by itself, hence is known as self reduction.
\[\begin{align}
& 2PbO+PbS\xrightarrow{\Delta }3Pb+S{{O}_{2}}\uparrow \\
& PbS{{O}_{4}}+PbS\xrightarrow{\Delta }2Pb+2S{{O}_{2}}\uparrow \\
\end{align}\]