Question: Consider the sulphides HgS, PbS, CuS, Sb$_{2}$S$_{3}$, As$_{2}$S$_{3}$ and CdS. Number of these sulp...

Question

Consider the sulphides HgS, PbS, CuS, Sb $_{2}$ S $_{3}$ , As $_{2}$ S $_{3}$ and CdS. Number of these sulphides soluble in 50% HNO $_{3}$ is _______.

Answer 1

Solution

Only the sulphides of Hg, Pb, and Cu are attacked by 50% HNO₃. Under the oxidizing conditions, these sulphides react with nitric acid to form their corresponding soluble nitrates and elemental sulphur or other oxidation products, while Sb₂S₃, As₂S₃, and CdS remain insoluble.