Normality Calculator
Pick a starting point, enter the equivalents per mole (valence) of your acid, base or salt and get normality, molarity and equivalents.
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Formula
equivalents = moles × nN = equivalents ÷ volume (L) = M × nM = N ÷ n
n is the number of equivalents per mole: H+ or OH- exchanged in an acid-base reaction, or electrons transferred in a redox reaction. The value depends on the reaction you are using.
Worked example
0.5 mol of H2SO4 in 2 L of solution, reacting with both protons (n = 2):
- equivalents = 0.5 × 2 = 1
N = 1 ÷ 2 =0.5 eq/L- molarity = 0.5 ÷ 2 = 0.25 mol/L, which also equals N ÷ n = 0.5 ÷ 2
Other checks: 0.1 M Ca(OH)2 (n = 2) is 0.2 N, and 1 N H3PO4 (n = 3) is 0.3333 M.
Frequently asked questions
What is normality?
Normality (N) is the number of equivalents of solute per litre of solution. An equivalent is one mole of the reactive unit, such as H+ or OH-. 0.5 mol of H2SO4 (2 equivalents per mole) in 2 L is 1 equivalent in 2 L, so 0.5 N.
How do I convert molarity to normality?
Multiply the molarity by the equivalents per mole: N = M × n. A 0.1 M Ca(OH)2 solution releases 2 OH- per formula unit, so it is 0.1 × 2 = 0.2 N.
What value do I use for equivalents per mole?
For acids and bases it is the number of H+ or OH- released per formula unit in the reaction (HCl 1, H2SO4 2, H3PO4 up to 3). For redox reactions it is the electrons transferred. It depends on the reaction, so one substance can have more than one normality.
How do I convert normality to molarity?
Divide by the equivalents per mole: M = N ÷ n. A 1 N phosphoric acid solution, taking all 3 protons, is 1 ÷ 3 = 0.3333 M.