Question

What is Rules For Assigning Oxidation Number?

Answer

The oxidation number of an atom can be calculated with the help of the following rules: (i) The sum of the oxidation numbers of all of the atoms in a neutral compound is 0. (ii) The oxidation number of a free element is always 0. The atoms in He and N2, for example, have oxidation numbers of 0. (iii) The convention is that the cation is written first in a formula, followed by the anion. For example, in NaH, the H is H-; in HCl, the H is H+. (iv) The oxidation number of a Group IA element in a compound is +1. (v) The oxidation number of a Group IIA element in a compound is +2.