Question

What is the oxidation number of a central metal atom $Na{H_2}P{O_2}$?

Answer 1

Hint: So we can say that the oxidation number is the number which has been allocated to the elements present in the chemical combination. It helps in determining the electrons which have been transferred. It also helps in determining the change which occurs during redox reactions.

Complete step by step answer:
Let us understand some of the terms before solving the question.
A metal complex consists of a central metal atom. A central metal atom is an ion bonded to one or more ligands. Ligands are the ions or molecules that contain one or more pairs of electrons and these electrons can be shared with the central metal atom.
The central metal atom is bound by the fixed number of Ions of the group in a definite geometrical arrangement.
Now let us understand what Oxidation state is.
Oxidation state is a degree of oxidation of an atom in a chemical compound. It is a hypothetical charge assuming that atoms will have no bonds at all and completely ionic. Oxidation states can be represented by an integer which can be positive negative and can also be zero.
The compound given in the question is:
$Na{H_2}P{O_2}$
It consists of one sodium atom, two hydrogen atoms, one phosphorus atom and two oxygen atoms.
The central atom in this compound is phosphorus.
Let the charge on phosphorus be x. The overall charge on the compound is 0.
The equation will be:
$1 + (1)2 + x + ( - 2)2 = 0 $
$ 1 + 2 + x + ( - 4) = 0$
$x = + 1 $

Hence, the charge on the central atom i.e. phosphorus is +1 .

Note: We can assign the oxidation state of the atom which has formed bonds with heteroatoms. It should form the ionic bonds by either losing or gaining electrons. The high charge on the atom would make it difficult to remove electrons from it.