Chemistry - General Principles and Processes of Isolation of Metals Question with Solution | TestHub

$\mathrm{P}\mathrm{b}\mathrm{O}$&$\mathrm{P}\mathrm{b}\mathrm{S}{\mathrm{O}}_4$get reduced by PbS itself which is already present in mixture so because the reduction took place by mixture itself, hence is known as self reduction.

$2\mathrm{P}\mathrm{b}\mathrm{O}+\mathrm{P}\mathrm{b}\mathrm{S}\stackrel{\mathrm{\Delta }}{\to }3\mathrm{P}\mathrm{b}+\mathrm{S}{\mathrm{O}}_2\uparrow$

$\mathrm{P}\mathrm{b}\mathrm{S}{\mathrm{O}}_4+\mathrm{P}\mathrm{b}\mathrm{S}\stackrel{\mathrm{\Delta }}{\to }2\mathrm{P}\mathrm{b}+2\mathrm{S}{\mathrm{O}}_2\uparrow$

While Sn is obtained by carbon reduction from$\mathrm{S}\mathrm{n}{\mathrm{O}}_2$.

$\mathrm{S}\mathrm{n}{\mathrm{O}}_2+2\mathrm{C}\stackrel{\mathrm{\Delta }}{\to }\mathrm{S}\mathrm{n}+2\mathrm{C}\mathrm{O}$