Exams › JEE Advanced › Chemistry

From the following ions, how many can be precipitated as sulfides from an acidic solution by passing H2S gas? Cd²+, Co²+, Cu²+, Ca²+, Mn²+, Mg²+, As³+, Al³+, Cr³+, Bi³+

1. 2
2. 3
3. 4
4. 5

Correct answer: 4

Solution

In acidic solution H2S provides a low [S²-] sufficient only to exceed Ksp of the most insoluble sulfides (Group II). From the given list: Cu²+ (CuS — very insoluble), Cd²+ (CdS — very insoluble), As³+ (As2S3 — very insoluble), Bi³+ (Bi2S3 — very insoluble) precipitate in acidic medium. Co²+ (CoS), Mn²+ (MnS) require near-neutral conditions (Group III). Ca²+, Mg²+, Al³+, Cr³+ do not form sulfide precipitates under these conditions. Total = 4.

Related JEE Advanced Chemistry questions

• The count of d-electrons in Fe2+ differs from the number of:
• Which sequence of reactions accurately depicts the chemical processes involving iron and its associated compounds?
• When H2S interacts with an acidic solution of K2Cr2O7, which of the following compounds is not produced?
• When an excess amount of sodium thiosulfate is combined with copper sulfate in water, the resulting product is:
• Among the given lanthanoid ions, which one exhibits diamagnetic behavior? (Atomic numbers: Ce = 58, Sm = 62, Eu = 63, Yb = 70)
• Which of these statements is accurate?

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →