What is equivalent weight?

The mass of a substance that reacts with or supplies one mole of reactive species (H+, OH-, or electrons).

How do I find the n-factor?

For acids: number of H+ donated. For bases: number of OH-. For salts in precipitation: total charge. For redox: electrons transferred.

Is equivalent weight still used?

Less so in modern chemistry, but it remains useful in titration calculations and water chemistry.

Free Equivalent Weight Calculator

Calculate the equivalent weight of a substance from its molar mass and n-factor.

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Molar Mass

g/mol

n-Factor

Equivalent Weight

49.040 g/equiv

Equivalent Weight vs Molar Mass

View formula & how it works →

How to Calculate Equivalent Weight

Formula

Equivalent weight = Molar mass / n-factor

The n-factor depends on the reaction type (acid-base, redox, etc.).

Example Calculation

H2SO4 (98.08 g/mol) as a diprotic acid (n=2).

01Eq. weight = 98.08 / 2
02Eq. weight = 49.04 g/equiv

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