Neutralization Calculator — Acid-Base Titration

Formula

How this is calculated

At the equivalence point of an acid–base titration, moles of acid equivalents (H⁺) exactly equal moles of base equivalents (OH⁻). For a monoprotic acid like HCl reacting with a monobasic base like NaOH, one mole of acid requires one mole of base. For polyprotic or polybasic species, multiply by the number of ionisable protons (n): H₂SO₄ has n = 2, Ca(OH)₂ has n = 2, and so on. The fundamental equation is n_a × M_a × V_a = n_b × M_b × V_b, which rearranges to find any unknown given the other four values.

This calculator solves for V_b — the volume of base required — given the acid parameters and the base molarity. It also estimates the total solution volume at the equivalence point and the approximate salt concentration (moles of acid equivalents divided by total volume). The salt concentration assumes complete reaction and no volume change on mixing, which is a standard approximation for dilute solutions.

Important limitations: the result gives the stoichiometric equivalence point only; it does not predict the final pH (which depends on whether the salt formed is acidic, basic, or neutral). The model also assumes ideal solution behaviour, no side reactions, and that the listed equivalents correctly describe the ionisation of the specific acid and base you are using.