Question

The chloro – bis (ethylenediamine) nitro cobalt (III) ion is:
(A) ${\left[ {Co{{\left( {N{O_2}} \right)}_2}{{\left( {en} \right)}_2}C{l_2}} \right]^ + }$
(B) ${\left[ {CoCl{{\left( {N{O_2}} \right)}_2}{{\left( {en} \right)}_2}} \right]^ + }$
(C) ${\left[ {Co\left( {N{O_2}} \right)Cl{{\left( {en} \right)}_2}} \right]^ + }$
(D) ${\left[ {Co\left( {en} \right)C{l_2}{{\left( {N{O_2}} \right)}_2}} \right]^ - }$

Answer 1

Since this is a complex compound . To get the formula for the given compound, we will look at the presence of ligands, elements and the overall charge on the ion.

Complete step by step answer:
The Chlorobis (ethylenediamine) nitro cobalt (III) ion is:
${\left[ {Co\left( {N{O_2}} \right)Cl{{\left( {en} \right)}_2}} \right]^ + }$
The Prefix bis represents that two ligands of the same type are present.
That is, there are two ethylene diamine ligands present.
The Oxidation state of Cobalt $\left( {Co} \right)$ is $+ 3$.
One chloride ligand and one nitro ligand are present. The presence of these two have $- 2$ charge.
To maintain the balance of the charges of ligands, the complex ion will have $+ 1$ charge.

So, the correct answer is Option C.

Additional Information:
The IUPAC name is written according to the following rules:
1. The Cationic part of the complex is written first.
2. Ligands are written according to the alphabetical order.
3. According to the presence of the number of ligands prefix such as di, tri, are used in case of mono dentate ligands.
4. In case of bidentate ligands, prefixes such as bis, tris are used.
5. For negative ligands such as chloride the name changes to chloro / chlorido.
6. If metal is anionic such as chromium the name becomes chromate.
7. Oxidation state is written in Roman Numerals.

Note:
For writing IUPAC name of the complex, the above-mentioned rules should be kept in mind and oxidation should be calculated wisely