ChemBench

Normality Calculator

Concentration measured in reactive equivalents.

Molarity (mol/L)

Equivalents per mole

Normality

2 N

What you entered

Molarity (mol/L): 1Equivalents per mole: 2

1
Normality = molarity × equivalents per mole
1 × 2= 2 N

Result

Normality: 2 N

This solution's normality is 2 N.

Normality of common lab reagents from their molarity and equivalents per mole

Normality is molarity multiplied by the number of reactive equivalents each mole supplies, which is exactly what the calculator computes. For acids and bases an equivalent is one replaceable H+ or OH-; for the two oxidising agents at the bottom it is one mole of electrons transferred.

Reagent	Equivalents per mole	Molarity (M)	Normality (N)
Hydrochloric acid, HCl	1	1.00	1.00
Nitric acid, HNO3	1	0.50	0.50
Sodium hydroxide, NaOH	1	1.00	1.00
Acetic acid, CH3COOH	1	0.10	0.10
Sulfuric acid, H2SO4	2	0.50	1.00
Concentrated sulfuric acid	2	18.00	36.00
Calcium hydroxide, Ca(OH)2	2	0.10	0.20
Sodium carbonate, Na2CO3	2	0.25	0.50
Phosphoric acid, H3PO4	3	0.50	1.50
Potassium permanganate, KMnO4 (acidic)	5	0.02	0.10
Potassium dichromate, K2Cr2O7 (acidic)	6	0.10	0.60

For any reagent with one equivalent per mole the normality and the molarity are the same number, which is why HCl and NaOH read identically in both columns. The equivalents figure is not a fixed property of the compound: it depends on the reaction. H3PO4 counts as 3 only if all three protons are titrated, and behaves as 1 or 2 when the titration stops at the first or second equivalence point. KMnO4 accepts 5 electrons in acid but only 3 in neutral or basic conditions, and K2Cr2O7 accepts 6 in acid. Decide the reaction first, then the equivalents. Concentrated sulfuric acid is quoted at a nominal 18 M; always check the assay on the bottle, and note that IUPAC now prefers molarity, so normality survives mainly in titration, water-testing and clinical lab procedures.

Molarity scaled by reactive capacity

Normality multiplies molarity by how many 'equivalents' (reactive units, like replaceable H⁺ ions in an acid) each mole of the substance provides — sulfuric acid (H₂SO₄) has 2 equivalents per mole since it can donate 2 protons.

Why it's used in titrations

Normality is convenient in acid-base and redox titrations because 1 equivalent of acid always exactly reacts with 1 equivalent of base, regardless of how many protons each specific molecule carries.

Frequently asked questions

A 0.5 M solution of H2SO4 — what is its normality?

H2SO4 has 2 equivalents per mole (it can donate 2 H+ ions). Normality = 0.5 M × 2 = 1.0 N.

How is normality different from molarity?

Normality scales molarity by the number of reactive units per molecule. For HCl (1 equivalent), N = M. For H3PO4 (3 equivalents if fully dissociated), N = 3 × M. Use the molarity calculator when you just need moles per liter.

Is normality still commonly used?

It has fallen out of favor in modern chemistry education and IUPAC recommendations, but remains widely used in titration procedures, water quality testing, and clinical labs because it simplifies equivalence-point calculations.

What are 'equivalents' for a redox reaction?

In redox chemistry, one equivalent is the amount of substance that gains or loses one mole of electrons. KMnO4 in acidic solution accepts 5 electrons per molecule, so it has 5 equivalents per mole.