Question
Among Fe^ 3+ , Pb^ 2+ , Cu^ 2+ and Mn^ 2+ , identify the one that gets precipitated out while passing H_2S in presence of NH_4OH as group reagent. The highest possible oxidation state of the corresponding metal is
JEE Main
Chemistry
Practical Chemistry
2026
JEE Main 2026 (04 April Shift 2)
JEE Main Chemistry Question (2026) — Solution
Options
- A. +3
- B. +4
- C. +2
- D. +7
Answer
D. +7
Step-by-step solution
The group reagent H_2S in the presence of NH_4OH is used for the precipitation of Group IV cations in qualitative analysis. Among the given ions, Mn^ 2+ belongs to Group IV and is precipitated as MnS. Pb^ 2+ and Cu^ 2+ belong to Group II and are precipitated by H_2S in an acidic medium. Fe^ 3+ belongs to Group III and is precipitated as Fe(OH)_3 by NH_4OH in the presence of NH_4Cl. The metal corresponding to the precipitated ion is Manganese (Mn). The electronic configuration of Mn is [Ar] 3d^5 4s^2. By losing all its valence electrons, it can exhibit a maximum oxidation state of +7 (for example, in KMnO_4). Answer: +7
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