Question 30
Qualitative AnalysisWhich of the following sulphides is insoluble in dilute HCl?
- A.Na2S
- B.ZnS
- C.CuS
- D.FeS
Show the answer and explanation
Answer: C (CuS)
Explanation
Copper (II) sulphide is so insoluble that dilute acid does not dissolve it (it is precipitated from acid solution in group analysis). Na2S, ZnS and FeS dissolve, giving H2S.