Calculation of oxidation Number in Redox Reactions
Oxidation number of the element is defined as the residual charge which its atom has when all other atoms from the molecule are assumed to be removed as ions.
General oxidation number of different groups are as follows:
IIIA +3/ +1
IV A – 4 to +4
V A – 3 to +5
VI A – 2 to +6
VII A – 1 to + 7
Oxidation Number / Oxidation state is never more than the group in which the element is present.
For neutral molecules like (water) and carbon mono oxide, Oxidation state is O.
If Hydrogen is attached with metal then its O. S is –1 and if it is attached with non – metal then its 0.5 is +1 oxygen can show 3 oxidation states.
Oxide Peroxide Superoxide
Use of Oxidation Number
1. Calculation of oxidation Number of elements underlined in the following species –
Let be the oxidation number of underlined element.
For this take
In this 2 Peroxide links are present and one oxide
We can write it as
2. In the Name of the compound
If the compound is in low oxidation state then suffix ‘ous’ is added
(III) If we get talk about mixing of 2 oxidation states