Among PbS, CuS, HgS, MnS, , NiS, CoS, and , the total number of BLACK coloured sulfides is
← JEE Advanced 2014 · Paper 1
ChemistryInteger+3Question 33 of 60
JEE Advanced 2014 · Paper 1, Chemistry question 33
Answer and worked solution
Official answer: 6
Colours.
| Sulphide | Colour |
|---|---|
| PbS | black |
| CuS | black |
| HgS | black (the precipitate) |
| MnS | pink / buff |
| Ag₂S | black |
| NiS | black |
| CoS | black |
| Bi₂S₃ | dark brown to black |
| SnS₂ | yellow |
Six are clearly black. Bi₂S₃ is usually called dark brown, but often described as black, so the official key accepts 6 or 7.
Answer: 6 (key: 6 or 7)
Topics:Cation analysis