How this calculator works
Normality counts reactive equivalents per litre. Define the reaction first: an acid-base equivalent represents one mole of H+ transferred, while a redox equivalent represents one mole of electrons. Equivalent mass is molar mass divided by the number of equivalents per formula unit for that reaction. Use final solution volume, not the volume of solvent poured in. The unit selector represents moles of reactive equivalents, and the separate eq/L output gives conventional N.
Formula
Equivalent mass E = molar mass / equivalents per formula unit. N(eq/L) = mass(g) / [E(g/eq) x volume(L)].
Worked example
Four grams with equivalent mass 40 g/eq in 1 L gives 0.1 N. A 0.5 N solution with E = 20 g/eq requires 10 g per litre.
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Frequently asked questions
Is normality always equal to molarity?
Only when one mole of the solute supplies one equivalent in the stated reaction.
Does sulfuric acid always supply two equivalents?
Complete neutralization supplies two; a different endpoint can correspond to a different reaction factor.
Does this calculate final pH?
No. Use the titration tool for acid-base mixing and equilibrium.