Question

In presence of PbS and ZnS in a mineral the froath 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
$ZnS+4NaCN\to 4N{a}^{+}+\left[Zn\right(CN{)}_4]2^{-}+S^{-2}$ Water soluble