Define normality ...plz also give an …

Normality in chemistry is one of the expressions used to measure the concentration of a solution. It is abbreviated as ‘N’ and is sometimes referred to as the equivalent concentration of a solution. It is mainly used as a measure of reactive species in a solution and during titration reactions or particularly in situations involving acid-base chemistry.

Example: 

n the following reaction calculate and find the normality when it is 1.0 M H₃PO₄

H₃AsO₄ + 2NaOH → Na₂HAsO₄ + 2H₂O

Solution:

If we look at the given reaction we can identify that only two of the H⁺ ions of H₃AsO₄ react with NaOH to form the product. Therefore,  the two ions are 2 equivalents. In order to find the normality, we will apply the given formula.

N = Molarity (M) × number of equivalents

N = 1.0 × 2 (replacing the values)

Therefore, normality of the solution = 2.0.