↪ In terms of O.N., oxidation is a chemical process which involve increase in O.N. .
Reduction is a chemical process which involves decrease in O.N. .
⁕ Oxidizing and Reducing Agent in terms O.N.
↪ An oxidizing agent or oxidant is a substance which oxidizes the other substances and itself get reduced.
↪ In other word, it is a substance whose O.N. decreases.
↪ An oxidizing agent is a species which gains electron.
↪ A reducing agent or reductant is a substance which reduces other substance and itself gets oxidized.
↪ In other words, reducing agent may be defined as the substance whose O.N. increases.
A reducing agent is a species which loses electrons.
⁕ Differences between O.N. and Valency
|1. It is the charge appeared on the atom.|
eg: O.N. of C in HCHO is 0.
|1. It is the no. of electrons lost, gained or shared by an atom of an element.|
eg: Valency of C in HCHO is 4.
|2. It may be zero, positive, negative or even in fraction.|
eg: O.N. of N in (hydrozoic acid) N3H is -1/3 and in NH3 is -3.
|2. It is a whole number with positive or negative sign.|
eg: Valency of N in N3H and NH3 is 3.
|3. It may be different for the same element in the different compounds.|
eg: O.N. of C in CH4, CH3Cl, CH2Cl2, CHCl3 and CCl4 are -4, -2, 0, +2 and +4 resp.
3. Except variable valency, elements have constant valency.