Titreringen

Titrering, or titration, is a laboratory technique in analytical chemistry used to determine the concentration of an unknown solution by reacting it with a solution of known concentration (the titrant). The method is based on a stoichiometric reaction between the analyte and the titrant and relies on detecting the point at which the reaction is complete, known as the end point or equivalence point.

Conventional titration uses a burette to deliver the titrant to the analyte contained in a flask or beaker. The titrant is added gradually while the reaction mixture is stirred. The end point is identified by a physical signal: a color change produced by an indicator or, in more advanced setups, a measurable change in pH, electrical conductivity, or potential recorded by a sensor. The choice of indicator depends on the specific reaction and the expected pH at the equivalence point.

Common types include acid-base titration, redox titration, complexometric (e.g., EDTA) titration, and precipitation titration. Calculations are based on the stoichiometry of the reaction. For a simple monoprotic acid–base titration, Ma Va = Mb Vb, where Ma and Va are the molarity and volume of the analyte and Mb and Vb are those of the titrant. For polyprotic or non-1:1 reactions, the equation uses equivalents.

Applications include determining concentrations in chemical, environmental, pharmaceutical, and food samples. Accuracy depends on proper calibration, correct indicator or sensor choice, careful burette technique, and control of temperature and reaction kinetics.