Question

In presence of PbS and ZnS in a mineral, the froth floatation process require NaCN because-

• A. ZnS goes into the solution as soluble complex $\left[Zn\right(CN{)}_4{]}^{2-}$
• B. $Zn(CN{)}_2$ is precipitated
• C. PbS forms soluble complex $N{a}_2\left[Pb\right(CN{)}_4]$
• D. ZnS forms insoluble complex $\left[Zn\right(CN{)}_4{]}^{2-}$

Answer 1

The correct option is A ZnS goes into the solution as soluble complex $\left[Zn\right(CN{)}_4{]}^{2-}$

ZnS forms water soluble complex $ZnS+4NaCN\to 4N{a}^{+}+\left[Zn\right(CN{)}_4{]}^{-2}\left(Watersoluble\right)+S^{-2}$