Find the base volume that neutralizes an acid, matching equivalents for polyprotic acids and bases.
Result
How to use this tool
Enter acid molarity, volume in mL, and equivalents per mole (1 for HCl, 2 for H₂SO₄).
Enter base molarity and equivalents per mole (1 for NaOH, 2 for Ca(OH)₂).
Read the base volume needed, with moles and equivalents for checking.
Add the base slowly near the endpoint and confirm with an indicator or pH meter.
Formula & worked example
50 mL of 0.1 mol/L HCl needs 50 mL of 0.1 mol/L NaOH; 50 mL of 0.1 mol/L H₂SO₄ needs 100 mL of 0.1 mol/L NaOH because each mole of H₂SO₄ carries two equivalents.
Limitations — read this before you rely on it
Assumes complete, single-step neutralization and ideal solutions. Weak-acid/base equilibria, activity effects and indicator error are not modelled.
Frequently asked questions
Equivalents: acid moles × equivalents per mole must equal base moles × equivalents per mole at the equivalence point.
Each H₂SO₄ gives 2 H⁺, so one mole neutralizes twice the base that one mole of HCl does.
Only for a strong acid with a strong base. Weak acids or bases give an equivalence pH above or below 7.
Millilitres, matching the acid volume unit; molarities are in mol/L.
No: it plans the titration. Real endpoints depend on indicator choice and solution purity.