Coordination Compounds

The cyano and hydroxo complexes are far more stable than those formed by halide ion. This is due to the fact that $C{N^ - }$ and $O{H^ - }$ are strong lewis bases (nucleophiles). Further ${\left[ {Fe{{\left( {OH} \right)}_5}} \right]^{3 - }}$ is not formed. hence most stable ion is ${\left[ {Fe{{\left( {CN} \right)}_6}} \right]^{3 - }}$

Compounds that contain at least one carbon metal bond are known as organometallic compounds. In $C{H_3}$$ - Mg - Br$ (Grignard's reagent) a bond is present between carbon and $Mg$ (Metal) hence it is an organometallic compound.

The chemical formula of nitropentammine chromium $\left( {{\rm I}{\rm I}{\rm I}} \right)$ chloride is

$\left[ {Cr{{\left( {N{H_3}} \right)}_5}\,N{O_2}} \right]C{l_2}$

It can exist in following two structures

$\left[ {Cr{{\left( {N{H_3}} \right)}_5}N{O_2}} \right]C{l_2}\,\,$ and

nitropentammine chromium $\left( {{\rm I}{\rm I}{\rm I}} \right)$ chloride

$\left[ {Cr{{\left( {N{H_3}} \right)}_5}ONO} \right]C{l_2}$

Nitropentammine chromium $\left( {{\rm I}{\rm I}{\rm I}} \right)$ chloride

Therefore the type of isomerism found in this compound is linkage isomerism as nitro group is linked through $N$ as $ - N{O_2}$ or through $O$ as $ - ONO.$

The brown ring complex compound is given as [Fe(H₂O)₅(NO)⁺]SO₄. To determine the oxidation state of iron (Fe) in this complex, we need to analyze the components and their charges:

1. Let the oxidation state of Fe be $x$.

2. The water molecules (H₂O) are neutral ligands; hence, they do not contribute to the overall charge.

3. The nitrosyl ligand (NO) in this complex is positively charged, $NO^+$, contributing a +1 charge.

4. The sulfate ion (SO₄) is doubly charged, with a -2 charge.

The overall charge of the complex compound, [Fe(H₂O)₅(NO)⁺], must balance the charge of the sulfate ion (SO₄):

Since the sulfate ion $SO_4^{2-}$ has a charge of -2, the complex ion must have a charge of +2 to balance it out:

Therefore:

$ x + 5(0) + 1 = +2 $

$ x + 1 = +2 $

$ x = +1 $

Thus, the oxidation state of iron (Fe) in the brown ring complex compound is +1.

The correct answer is:

Option A

1