Question

The sum of coordination number and the oxidation number of the metal $M$ in the complex $[M{\left( {en} \right)_2}\left( {{C_2}{O_4})} \right]Cl$ (where $en$ is ethylenediamine) is:
A. $7$
B. $8$
C. $9$
D. $6$

Answer 1

We have to remember that the coordination compound contains coordinate bonds, the bond is between a central metal atom and the number of other atoms or groups, and it is called coordination center. And, in the coordination compound, the surrounding bound molecule or ions are known as ligands or complexing agents.

Complete step by step answer:
We must remember that in the coordination compound, the total number of ligands or complexing agents attached to a central metal atom is called the coordination number.
For example, the coordination number of ${[Fe{(CN)_6}]^{4 - }}$ is $6$ . Six $C{N^ - }$ ions are attached to the central metal atom, $Fe$ .
Oxidation state of the central metal atom is calculated from below format,
For the compound, ${[Fe{(CN)_6}]^{4 - }}$ .
Let X be the oxidation number, $C{N^ - }$ oxidation number is $- 1$ , then
$X + 6( - 1) = - 4$
$X = 2$.
The Given compound, $[M{\left( {en} \right)_2}\left( {{C_2}{O_4})} \right]Cl$ , contains $en$ , ${C_2}{O_4}$ and $Cl$ . Where $en$ and ${C_2}{O_4}$ are bidentate ligand, $Cl$ is a unidentate ligand, but the oxidation number of $en$ is zero, ${C_2}{O_4}$ is $- 2$ and $Cl$ is $- 1$ .
Coordination number of $[M{\left( {en} \right)_2}\left( {{C_2}{O_4})} \right]Cl$ complex is $2(2) + 2 = 6$.
Oxidation state of $[M{\left( {en} \right)_2}\left( {{C_2}{O_4})} \right]Cl$ is calculated as,
$X + 2(0) + ( - 2) = - 1$
$X = + 3$
The coordination number and the oxidation number of the metal $M$ in the complex $[M{\left( {en} \right)_2}\left( {{C_2}{O_4})} \right]Cl$ is $6$ and $+ 3$ .
The sum of Coordination number and the oxidation number of the $[M{\left( {en} \right)_2}\left( {{C_2}{O_4})} \right]Cl$ is,
$6 + 3 = 9$
Therefore, option C is correct.

Note:
We need to remember that the benzoylation of any benzene moiety having at least one hydrogen atom bonded to electronegativity atom. Benzoylation in benzene compared to another benzene derivative is less reactive. Because all the hydrogen is having the same electronegativity. Benzoylation is an important reaction for forming larger benzene moieties. In new drug designing purposes, most of the scientists use these techniques for synthesis of new molecules. In this reaction, larger benzene moiety is also applicable.