JEE Main · 2023 · 24 Jan 2023 · Shift 1 · Coordination Compounds

An ammoniacal metal salt solution gives a brilliant red precipitate on addition of dimethylglyoxime. The metal ion is :

(A) $Cu^{2 +}$
(B) $Co^{2 +}$
(C) $Fe^{2 +}$
(D) $Ni^{2 +}$ ✓ Correct

Answer: (D)

Solution

Dimethylglyoxime is the specific reagent for nickel: in an ammoniacal medium nickel(II) chelates two dimethylglyoxime units into an insoluble square-planar complex of a brilliant rosy-red colour. The metal ion giving this test is nickel(II).

JEE Main · 2023 · 24 Jan 2023 · Shift 1 · Single correct option

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