NaCN is sometimes added in the froth floatation process as depressant when ZnS and…

CHEMISTRY · Single correct · CBSE · Chemistry · Metals and Non-metals · Metals and Non-metals

Problem

NaCN is sometimes added in the froth floatation process as depressant when ZnS and PbS minerals are expected because : (1)

Pb(CN)_2

is precipitated while no effect on ZnS (2) ZnS forms soluble complex

Na_2[Zn(CN)_4]

while PbS forms froth (3) PbS forms soluble complex

Na_2[Pb(CN)_4]

while ZnS forms froth (4) NaCN is never added in froth floatation process