Question

What is the oxidation number of carbon in $C{N^ - }$ ? (Give the absolute value)

Answer 1

The oxidation number of a central element can be found out in a given compound. The single compound is responsible for having specific reactions like the redox processes in the chemical actions. The increase or decrease in the oxidation number in a specific reaction defines oxidation and reduction of the given compound.

Complete step by step solution:
The oxidation number of carbon from the given ligand $C{N^ - }$ can be calculated using the specific oxidation number of nitrogen. The ligand is responsible for forming bonded structure with the central metal ions forming the complex structures. The charge of the ion is responsible for finding out the oxidation number of $C$ which is why for the ligand the other factors about the charge need to be known.
Let us consider that the carbon $\left( C \right)$ in the cyanide ion has the oxidation number as $X$ . The oxidation number of the nitrogen $\left( N \right)$ is predetermined as $- 3$ . The charge of the whole $C{N^ - }$ ion is $- 1$ which needs to be included in the equation for the calculation of oxidation number. Therefore, from the given formula of the oxidation number equating the oxidation number of the two elements with the whole charge of the cyanide ion will be:
$X + \left( { - 3} \right) = - 1$
$\Rightarrow X - 3 = - 1$
$\Rightarrow X = + 3 - 1$
$\Rightarrow X = + 2$
The resultant oxidation number of the carbon residue which is present in the cyanide ion is $+ 2$ . This is only for the carbon which is associated with the cyanide ion. This oxidation number is an important part of the chemical structure of the cyanide ion.

Note:
Simple factors about the oxidation number of a given element is that it differs from one compound to another. This is because the oxidation state differs depending on the other elements that form the compound with the central element.