Question

ZnS is always contaminated with PbS. We add $NaCN+ZnS$ to enrich PbS by froth flotation process. If true enter 1 else 0.

Answer 1

$\underset{\left(ZincBlende\right)}{ZnS}$ is always contaminated with $\underset{\left(Galena\right)}{PbS}$

Galena is concentrated by using a collector, potassium ethyl xanthate and sodium cyanamide and alkali as depressant. This is froth flotation process. Hence its True, 1.