Normality Calculator

Normality (N) is a measure of concentration equal to the gram equivalent weight per liter of solution. It accounts for the number of reactive units (H⁺, OH⁻, electrons) that participate in a chemical reaction. For a 1 M solution of HCl (1 H⁺), N = 1, but for 1 M H₂SO₄ (2 H⁺), N = 2.

Normality is particularly useful in acid-base titrations, redox reactions, and precipitation reactions where the number of equivalents matters. It simplifies stoichiometric calculations because 1 equivalent of acid always neutralizes 1 equivalent of base, regardless of their molecular formulas.

Use N = M × n, where n is the number of equivalents per mole. For HCl: N = M (since n = 1). For H₂SO₄: N = 2M (since n = 2). To convert back, use M = N / n.

Yes, weak acids like acetic acid (CH₃COOH) and weak bases like ammonia (NH₃) can have normality. The number of equivalents is determined by the number of ionizable H⁺ or OH⁻ ions, not by the strength of the acid or base. For CH₃COOH, n = 1, so N = M.

While molarity is more commonly used in modern chemistry, normality remains useful in analytical chemistry, particularly for titrations. It's still taught in chemistry courses and used in some laboratory procedures, though it's gradually being replaced by molarity and other SI units.

In redox reactions, the number of equivalents equals the number of electrons transferred. For KMnO₄ reducing from Mn⁷⁺ to Mn²⁺, it gains 5 electrons, so n = 5. A 0.1 M KMnO₄ solution would be 0.5 N in this reaction.