Consider the following test for a group-IV cation. M^2+ + H2S → A (Black precipitate) + byproduct

Question

Consider the following test for a group-IV cation.

\(M^{2+}+ H_2S \rightarrow A\) (Black precipitate) + byproduct 

A + aqua regia \(\rightarrow\) B + NOCl + S + \(H_2O\) 

B + \(KNO_2\) + \(CH_3COOH \rightarrow C\) + byproduct 

The spin only magnetic moment value of the metal complex C is ______BM. 

(Nearest integer)

Answer 1

Correct answer is : 0

If \(M^{+2} = Co ^{+2}\)

then

\(Co^{+2} + H_2S \rightarrow \underset {\underset {[A]}{Black\,ppt}}{CoS} + byproduct\)

\(CoS + aqua \, regia \rightarrow \underset {[B]}{CoCl_2}+NOCl + S + H_2 O\)

\(CoCl_2 + KNO_2 \rightarrow \xrightarrow {CH_3 COOH} k_3 [CO(NO_2)_6] + byproduct\)

\([C] = Co ^{+3} \rightarrow 3d ^6 \Rightarrow NO_2 \) is SFL so Co+3 has zero unpaired \(e^-\)

\(\Rightarrow n = 0 \Rightarrow u = \sqrt {n {(n+2)}} = 0 \, B.M\)