Normality Calculator
Normality from molarity and equivalents — the concentration unit titrations still use, and how it relates to molarity.
Normality is molarity multiplied by the number of reactive equivalents per mole.
How the normality calculator works
Normality is molarity multiplied by the number of reactive equivalents per mole. Sulfuric acid donates two protons, so 1 M H₂SO₄ is 2 N.
It exists because titration arithmetic becomes trivial: at the endpoint N₁V₁ = N₂V₂, whatever the stoichiometry. The cost is ambiguity — normality depends on the reaction, so the same solution can be 1 N in one context and 3 N in another. Most standards bodies now discourage it.
Formula: N = M × equivalents; N₁V₁ = N₂V₂
Worked examples
| Inputs | Normality | Note |
|---|---|---|
| 1 M sulfuric acid | 2 N | 2 N |
| 1 M hydrochloric acid | 1 N | 1 N — the same either way |
| From a mass | 2 N | 1 M, 2 N |
FAQFrequently asked questions
What is normality?
Molarity times the number of reactive equivalents per mole. For acids that is the number of protons donated.
Why is 1 M sulfuric acid 2 N?
Because each molecule donates two protons, so a mole supplies two equivalents.
Why is normality discouraged now?
Because it depends on the reaction, not just the solution. Potassium permanganate is 5 N in acid and 3 N in neutral conditions — the same bottle.
What is equivalent weight?
Molar mass divided by equivalents. For sulfuric acid it is 49.04 g per equivalent.
Why does titration still use it?
Because N₁V₁ = N₂V₂ holds regardless of stoichiometry, which makes endpoint arithmetic trivial. That convenience is why it persists.
Where these figures come from
- IUPAC — Standard atomic weights (2021 conventional values) — the molar-mass table
- NIST — CODATA 2018 fundamental physical constants — Avogadro constant, gas constant, speed of light
- NIST Chemistry WebBook — thermochemical data
- National Institute of Standards and Technology — the US measurement and reference-data authority
Last checked: September 2026. Atomic masses are the IUPAC conventional values; constants are CODATA 2018; equations are the standard textbook forms.