Titraatio

Titraatio, also known as titration, is a quantitative analytical technique used to determine the concentration of a solute in a solution by adding a titrant of known concentration until the reaction reaches completion. A measured sample, the analyte, is placed in a flask, and a burette is used to deliver the titrant.

The method relies on a defined chemical reaction between the analyte and the titrant. The endpoint is the observed signal indicating that the reaction has reached completion, such as a color change of an indicator or a measurable shift in pH or redox potential. The equivalence point is the theoretical moment when the reactants have been consumed in the correct stoichiometric ratio; the end point should closely approximate this point for accurate results.

Common titration types include acid–base titrations, redox titrations, and complexometric titrations (for example with EDTA). Indicators are chosen to provide a visible signal in acid–base titrations (such as phenolphthalein or methyl orange), while more precise detection often uses pH meters or redox sensors.

Procedure and calculation: a known volume of analyte is placed in a flask, the burette is filled with titrant, and the titrant is added gradually with swirling until the endpoint is reached. The volume of titrant used is recorded, and the concentration of the analyte is calculated from the stoichiometry: the amount of titrant equals the amount of analyte at the equivalence point, so C_titrant × V_titrant = C_analyte × V_analyte, adjusted for the appropriate stoichiometric coefficients.

Applications and notes: titration is widely used in chemistry, biology, environmental science, medicine, and industry for concentration determination and quality control. Precision depends on careful technique, proper calibration, and appropriate indicator or sensor selection.