Question

`NaCN` is sometimes added in the froth flotation process as a depressant when `ZnS` and `PbS` minerals are expected because `:`
A. `Pb(CN)_(2)` is precipitated whhile no effect on `ZnS`.
B. `ZnS` forms solubel complex `Na_(2)[Zn(CN)_(4)]` while `PbS` forms froth.
C. `PbS` froms soluble complex `Na_(2)[Pb(CN)_(4)]` while `ZnS` forms froth.
D. `NaCN` is never added in froth floatation process.

Answer 1

Correct Answer - 2
`ZnS+4NaCNrarrNa_(2)[Zn(CN)_(4)]+Na_(2)S`
`PbS+NaCNrarr`No such complex formation