Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Widmer (Deceased), M. 2006. Titrimetry. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
In a titration, the analyte reacts with a reagent added as a solution of known concentration. The standard solution added from a buret is called a titrant. The volume of the titrant required to react completely with the analyte is measured as the volume at the equivalence point. The notions titrimetry and volumetry have the same meaning. Only well-defined stoichiometric reactions are applied. No additional calibration is necessary, i.e. titrimetric methods are primary methods. Indication of the equivalence point can be carried out by visual indicators or instrumental methods.
Acidimetric and alkalimetric titrations can be described by Brønsted's theory of strong and weak acids and bases. Theoretical titration curves for reactions of strong or weak acids (bases) with strong bases (acids) are demonstrated. Extremely weak electrolytes can be titrated in the presence of precipitating, oxidizing or complexing agents.
Determinations of metal ions are feasible by means of complexometric titrations. The theory of complexometry, including coupled chemical equilibria, can be derived from the fundamentals of complex-formation reactions in aqueous solutions. Applications are important for analyzing individual metal ions, mainly for their standardization, or for determining the hardness of water.
With regard to the instrumental indications of a titration, the potentiometric, amperometric and conductometric principles are outlined. Amperometric titrations of metal ions are performed with one polarizable electrode. The use of two polarizable electrodes (biamperometry) is especially important to determine the water content of organic solvents.