Question

Discuss briefly giving an example, the role of coordination compound in

extraction of metals.

Answer 1

The process of extraction of some of the metals from their ores involves the formation of complexes.

For eg. in aqueous solution, gold combines with cyanide ions to form $\left[{Au\left(CN\right)}_2\right]$ from this solution, gold is later extracted by the addition of $Zn-$metal.

$4Au+{16CN}^{-}+6H_{2}O+O_2⟶{4\left[Au{\left(CN\right)}_2\right]}^{-}+{12OH}^{-}$

${\left[{Au\left(CN\right)}_2\right]}^{-}+Zn⟶{\left[{Zn\left(CN\right)}_4\right]}^{2-}+2Au$