Titration

Summary: A technique to determine the concentration of an unknown solution by reacting it with a solution of known concentration. Tags: igcse chemistry definition acids-bases stoichiometry Created: 2026-07-14 Last Updated: 2026-07-14

Titration is a quantitative analytical technique used to determine the unknown concentration of a solution by reacting it with a solution of known concentration (the standard solution or titrant) until the reaction reaches completion, as indicated by a colour change from a suitable indicator. The procedure uses a burette to deliver the titrant dropwise into a conical flask containing a precisely measured volume of the unknown solution (measured with a volumetric pipette, typically 25.0 cm³) and a few drops of indicator — phenolphthalein (colourless in acid, pink in alkali) or methyl orange (red in acid, yellow in alkali) for acid-base titrations. The endpoint is reached when the indicator changes colour, signalling that neutralisation is complete, and the volume of titrant used (the titre) is recorded to the nearest 0.05 cm³; the process is repeated until concordant results are obtained, meaning two or more titres agree within 0.1 cm³ of each other. Using the balanced chemical equation and the concordant titre value, the unknown concentration can be calculated by first finding the moles of the known solution and then applying the mole ratio from the equation to determine the moles, and hence concentration, of the unknown solution. Titration is the method of choice for preparing soluble salts of Group 1 metals and ammonium salts where both reactants are soluble and no excess reactant can be easily removed, and in IGCSE exams students must be able to describe the full procedure, identify the correct apparatus, and perform the associated mole calculations to determine an unknown concentration.

This is a key term definition page — part of the IGCSE Chemistry (0620/0971) keyword glossary.