What is the Difference Between Normality and Molarity?

Molarity and normality are both measures of concentration in chemistry, but they differ in their applications and how they are calculated. Here are the main differences between the two:

Definition: Molarity refers to the concentration of a compound or ion in a solution, measured as the number of moles of solute per liter of solution (mol/L). Normality, on the other hand, refers to the molar concentration only of the acid component or only of the base component of the solution. It is defined as the number of mole equivalents per liter of solution.
Application: Molarity is a general measure of concentration and can be used for all types of solutions, while normality is specifically used for acids and bases.
Calculation: To calculate molarity, you simply divide the number of moles of solute by the volume of the solution in liters. Normality, however, requires knowledge of the acid or base chemistry and the number of H+ or OH- ions involved in the reaction. The formula for calculating normality from molarity is: N = n × M, where n is an integer.
Relation between Normality and Molarity: Normality can be described as a multiple of molarity. In some cases, normality can provide a more in-depth understanding of the solution's concentration in acid-base reactions.

For example, a 1M solution of sulfuric acid (H2SO4) has a normality of 2N because it gives out 2 protons (H+) per molecule. In acid-base chemistry, identical volumes of any acid solution will exactly neutralize an equivalent volume of a base solution if their normalities are equivalent.