Normality is a measure of concentration used in chemistry, which expresses concentration in terms of the equivalents of one chemical species that react stoichiometrically with another chemical species/16%3A_Appendix/16.01%3A_Normality). Normality is defined as the number of gram or mole equivalents of solute present in one liter of a solution. It is abbreviated as ‘N’ and is sometimes referred to as the equivalent concentration. Normality is used in various chemical reactions, including acid-base chemistry, precipitation reactions, and redox reactions.
Some key points about normality in chemistry include:
- Normality is a measure of concentration equal to the gram equivalent weight per liter of solution.
- Normality is used to indicate hydronium ions (H3O+) or hydroxide ions (OH–) concentrations in a solution.
- Normality is not a proper unit of concentration in situations apart from the ones mentioned above. It is an ambiguous measure, and molarity or molality are better options for units.
- Normality requires a defined equivalence factor.
- The normality of a solution is never less than its molarity.
- The number of equivalents, n, used in normality calculations depends on the chemical reaction/16%3A_Appendix/16.01%3A_Normality).
To calculate normality from molarity, the formula is N = n x M, where N is normality, n is the number of equivalents, and M is molarity. The equivalent weight is the ratio of a chemical species’ formula weight to the number of its equivalents/16%3A_Appendix/16.01%3A_Normality).
