Question

What is an oxidation-reduction or redox reaction?

Answer 1

The reaction in which oxidation and reduction occurs simultaneously is known as redox reaction.

Answer 2

Answer:

Oxidation number or oxidation state : The oxidation number (or oxidation state) of an atom in a molecule or an ion is defined as the number of charges it would carry if the electrons were completely transferred.

Explanation:

(1) The oxidation number or oxidation state does not always imply ionic charges on the species.

(2) The oxidation number of monoatomic ion is equal to charge of the ion. For example, Na^+ has + 1 charge while Cl^- has 1 charge, Ca²^+ has +2 charge and so on (But the oxidation states are 1+, 1-, 2+ respectively).

(3) In case of a neutral molecule, the sum of the oxidation numbers of all the constituent atoms is always zero.

(4) The charge on a polyatomic ion is equal to the algebraic sum of the oxidation numbers of all the constituent atoms of the ion.

(5) From the change in the oxidation numbers in a redox reaction, an oxidant and a reductant can be identified.

[Note : Oxidation number or oxidation state is represented as 1+, 2+, etc. while charge is represented as +1, + 2, etc.)