Chemistry - Metallurgy Question with Solution | TestHub

Column I Column II (A) Self reduction $\left[\begin{array}{c}P\text{ - Lead }\\ R\text{ - Copper }\end{array}\right]$ $$\begin{array}{rl}& \text{ i.e., }A\rightleftarrows P\text{ and }R\\ & \text{ In lead metal }\\ & \{\begin{array}{c}2\mathrm{PbS}+3{\mathrm{O}}_2⟶2\mathrm{PbO}+2{\mathrm{SO}}_2\\ 2\mathrm{PbO}+\mathrm{PbS}⟶3\mathrm{Pb}+{\mathrm{SO}}_2\end{array}\end{array}$$ (self reduction) In copper metal $$\begin{array}{rl}& 2{\mathrm{Cu}}_2\mathrm{S}+3{\mathrm{O}}_2⟶2{\mathrm{Cu}}_2\mathrm{O}+2{\mathrm{SO}}_2\\ & {\mathrm{Cu}}_2\mathrm{S}+2{\mathrm{Cu}}_2\mathrm{O}⟶6\mathrm{Cu}+{\mathrm{SO}}_2\end{array}$$ (self reduction) (B) Carbon reduction $P$-lead $$\begin{array}{rl}& \text{ i.e., }\mathrm{B}-\mathrm{P}\\ & \text{ In lead metal }\\ & \mathrm{PbO}+\mathrm{C}⟶\mathrm{Pb}+\mathrm{CO}\\ & \mathrm{PbO}+\mathrm{CO}⟶\mathrm{Pb}+{\mathrm{CO}}_2\end{array}$$ Carbon reduction process is used for the reduction of oxides of electropositive metals like $\mathrm{Fe},\mathrm{Pb}$ etc. This reduction is carried out with coal or coke on strongly heating. (C) Complex formation and displacement by metal. i.e., $C-Q$ (silver) In silver metal Argentite mineral of $\mathrm{Ag}\left({\mathrm{Ag}}_2\mathrm{S}\right)$ is treated with $0.7\%\mathrm{NaCN}$ solution in presence of air, therefore firstly sodium argento cyanide complex is formed which on heating with zinc metal, therefore by displacement silver is isolated. $$\begin{array}{rl}& {\mathrm{Ag}}_2\mathrm{S}+4\mathrm{NaCN}⟶2\mathrm{Na}\left[\mathrm{Ag}(\mathrm{CN}{)}_2\right]+{\mathrm{Na}}_2\mathrm{S}\\ & 2\mathrm{Na}\left[\mathrm{Ag}(\mathrm{CN}{)}_2\right]+\mathrm{Zn}⟶\mathrm{Na}\left[\mathrm{Zn}(\mathrm{CN}{)}_4\right]+\underset{\text{ Soluble }}{2\mathrm{Ag}}\downarrow \end{array}$$ (D) Decomposition of iodide-(S) Boron $$\text{ i.e., }(D)-(S)$$ By decomposition of iodide boron metal is isolated.