Question

How do you calculate the oxidation number of an element in a compound?

Answer 1

Hint The charge on the atom or element is called the oxidation number of the particular element. If the atom has positive charge then the atom will have positive oxidation number and if the element have negative charge then the element will have a negative oxidation number.

Complete step by step answer:
- In the question it is asked how to calculate the oxidation number of an element in a compound.
- We know that the oxidation number of a free element is zero.
- The charge of the monatomic ion is nothing but the charge of the ion.
- The hydrogen has an oxidation of ‘+1’, and it will be ‘-1’ when it will react with an element which has less electronegative value then the hydrogen.
- The oxidation number of oxygen in the compound will be ‘-2’ and it will be ‘-1’ in peroxides.
- The oxidation number of all group I elements in a compound is ‘+1’.
- The oxidation number of group II elements in a compound is ‘+2’.
- The oxidation number of group XVII elements in all binary compounds is ‘-1’.
- In a neutral compound the sum of the oxidation state of all the atoms is zero.
- The sum of the oxidation numbers of all the atoms in a polyatomic ion is equal to the total charge of the ion.
- This is how we can calculate the oxidation number of an element in a compound.

Note: By knowing about the calculation of oxidation number we can find how many electrons are transferred in between the chemicals which are involved in the chemical reaction. By using oxidation number only we can find the number of electrons exchanged between the atoms in a chemical reaction.