In which of the following pair of metals, both are commerically extracted from their respective ores by self-reduction method?

Options

A. `Zn,Cu`
B. `Pb,Cu`
C. `Sn,Zn`
D. `A1,Ag`

Answer

B

Explanation

(i) Extraction of tin (carbon reduction):
`SnO_(2)+C rarr SnO +CO`
(ii) Extraction of zinc (carbon reduction):
`ZnO +C overset(coke,673)rarr Zn +CO`
(iii) Extraction of lead (self- reduction):
`PbS +2O_(2)rarrPbSO_(4)`,
`PbS +3O_(2)rarr 2PbO+2SO_(2)`,
`PbS + 2PbO rarr 3Pb + SO_(2)`,
`PbS + PbSO_(4) rarr 2Pb + 2SO_(2)`
(iv) Extraction of copper (self -reduction)
`2CuFeS_(2) + 4O_(2) rarr Cu_(2)S+2FeO +3SO_(2)`
`CU_(2)S +FEO +SiO_(2)rarrFeSiO_(3)` (fusible slag) `+Cu_(2)S` (matte)
`2Cu_(2)S +3O_(2)rarr 2Cu_(2)O +2SO_(2)`,
`2Cu_(2)O +Cu_(2)S rarr 6Cu +SO_(2)`
(v) Extraction of aluminium (electroytic reduction, Hall-Heroult process):
The purified `A1_(2)O_(3)` ia mixed with `Na_(3)A1F_(6)` (cryolite) or `CaF_(2)` (fluorspar) which lowers the melting point of the mixture and increases conductivity. The fused matrix is electrolysed.
Cathode: `A1^(3+) ("melt") +3e^(-) rarr A1(1)`
Anode: `C(s) +O^(2-) ("melt")rarr CO(g) +2e^(-)`
`C(s) +2O^(2-)("melt") rarr CO_(2) +4e^(-)`
(vi) Extraction of gold//silver (leaching and displacement method):
`4Au//Ag(s) +8CN^(-) (aq)+2H_(2)O(aq)+O_(2) (g) rarr 4[Au//Ag(CN)_(2)]^(-)(aq) +4OH^(-)(aq)`
`2(Au//Ag(CN)_(2)]^(-)(aq)+Zn(s) rarr 2Au//Ag(s) +[Zn(CN)_(4)]^(2-)(aq)`