Free · Mixtures and solutions calculators ⚗️

Equivalent Mass, Concentration & Solution Volume

Relate reaction-specific equivalent mass to solute mass, final solution volume and equivalent concentration.

  • Formula & worked example
  • Private in your browser
  • No signup
Go to tool

Calculator inputs

Loading calculator…

How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A solute mass of 10 g in 2 L at 0.1 eq/L corresponds to equivalent mass 50 g/eq.

Equivalent mass = solute mass / (equivalent concentration × final solution volume)

Worked example

Enter these known values and leave the other values blank.

Solute mass
10 g
Final solution volume
2 L
Equivalent concentration
0.1 eq/L
Reaction-specific equivalent mass
50 g / eq

Assumptions and limitations

  • All quantities are positive. Equivalent mass means mass per reaction-specific equivalent, rather than molar mass or equivalents per gram.
  • Use final solution volume, not solvent volume before dissolution. The equivalent-concentration field always uses eq/L even when another volume unit is selected.
  • Specify the reaction and equivalent entity. This mass balance does not calculate a titration endpoint, identify a reaction or infer the equivalence factor from a chemical name.

Common questions

Can one substance have different equivalent masses?

Yes. The equivalence factor depends on the specified reaction, such as the number of transferred electrons or reacted hydrogen ions.

Does this accept equivalents per gram?

No. The equivalent-mass input is grams per equivalent or another selected mass per equivalent. Take the reciprocal if your value is equivalents per mass.

References

Bookify replaces the captured rounded US gallon with the exact 3.785411784-liter definition. The US fluid ounce uses one 128th of the exact US liquid gallon, replacing the rounded captured reciprocal factor. The US customary cup uses one sixteenth of the exact US liquid gallon, replacing the rounded captured cup volume.

Explore mixtures and solutions calculators ⚗️ or browse all chemistry calculators.