Match the extraction processes listed in Column I with metals listed in Column II.
`{:("Column I","Column II"),(A. "Self reduction",p. "Lead"),(B. "Carbon reduction",q. "Silver"),(C. "Complex formation and displacement by metal ",r. "Copper"),(D. " Decomposition of iodide",s. "Boron"):}`

Answer

A, B, C, D

Explanation

"Selt reduction" " " `[{:(p, -"Lead"),(r,-"Copper"):}]`
In head metal
`{{:(,2PbS+3O_(2) to2PbO+2SO_(2)("Slef reduction")),(,2PO+PbS to 3Pb+SO_(2)):}`
In copper metal
`2Cu_(2)S+3O_(2) to 2Cu_(2)O+2SO_(2)`
`Cu_(2)S+2Cu_(2) to 6Cu_(2)+2SO_(2)` (Slef reduction)
(B) Carbon reduction p- Lead
In lead metal
`PbO+C to Pb+CO`
`PbO+CO to Pb+CO_(2)`
Carbon reduction process is used for the reduction of oxides of electropositive metals like , Fe, Pb etc. This reduction is carried out with coal or coke on strongly heating.
(C) Comlex formation and displacement by meta.
In silver metal
Average `(Ag_(2)S)` mineral of Ag is treated iwth `0.7% NaCN` solution in presence of air, therefore, firstly soldium argentocyanide compled is formed which on heating with zinc meta, therefore, by displacement silver is isolated
`Ag_(2)S+4NaCN to 2Na[Ag(CN)_(2)]+NaS`
`2Na[Ag(CN)_(2)]+Zn to underset("soluble")(Na_(2)[Zn(CN)_(4)])+2underset("ppt")(Ag)darr`
(D) Decomposition of iodide _______ (S) Boron By decomposition of iodide boron metal is isolated.
`2BI_(3)overset("Wm heat")to 2B+3I_(2)`