Titration

Titration is an experimental procedure. It consists of combining two reacting substances in stoichiometric quantities. The process can be used for any type of reaction between two substances. However, it is most commonly used for reactions between a traditional acid and a traditional base. The purpose of a titration is to determine the concentration of an unknown solution.

Titrations are traditionally performed in the laboratory using a buret. A buret is a calibrated glass tube that is open at the top, for filling, and has a stopcock at the bottom. The stopcock is a device that is used to drain liquid out of the buret under a controlled set of conditions. When the stopcock is opened, the liquid in the buret is usually drained into a beaker or flask that is located underneath it. The buret is usually clamped vertically to a ringstand, or some other form of stable structure. During a titration procedure, a known quantity of liquid is located in the beaker that is below the buret. The buret will contain the second substance, a material that will react with the material in the beaker. By knowning the quantity of liquid that is drained from the buret and the amount of liquid in the beaker, a series of mathematical procedures can be performed which will be useful in identifying some quality of the system. Usually, that quality is the concentration of the material in the beaker.

When performing a titration between an acid and a base, it is necessary to understand the concepts and mathematics behind the process. When an acid reacts with a base, the products will be a salt and water. Such a reaction could be represented by the simple combination of NaOH with HCl. In this reaction, the stoichiometry is one mole of HCl reacting with one mole of NaOH and forming one mole of NaCl. To facilitate the math associated with this type of process, the concept of the equivalent was created. One equivalent   is defined as one mole of acidic hydrogen or one mole of basic hydroxide. When doing a titration, one equivalent of acid will neutralize one mole of base!

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Updated September 1, 2000