olumetry . A chemical method of measuring how much of a solution is needed to react exactly with another solution of known concentration and volume. To do this, the unknown or ‘problem’ solution is added drop by drop to the other solution (titrated solution) from a cylindrical container called a burette, until the reaction ends.
Summary
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- 1 Etymology of the word
- 2 Classification according to the object to be analyzed
- 1 Acid-base titrations
- 2 Redox valuations
- 3 Evaluations of complex formation or complexometries
- 4 Precipitation Assessments
- 3 Laboratory supplies
- 4 Sources
Etymology of the word
Volumetric analysis is also called “Titration or Valuation”. The word “titulation” comes from the Latin word titulus, which means inscription or title. The French word titre, of the same origin, means rank or degree. Titration is the procedure used to determine the volume of a solution that is necessary to react with a certain amount of another substance.
Classification according to the object to be analyzed
Acid-base titrations
These are based on the neutralization reaction between the analyte and a reference acid or base solution. To determine the end point, they use a pH indicator , a pH meter, or a conductance meter.
Redox ratings
They are based on the oxidation-reduction reaction or redox reaction between the analyte and a reference oxidant or reducing solution. To determine the end point, they use a potentiometer or a redox indicator, although sometimes either the substance to be analyzed or the reference standard solution is sufficiently intense in color that an additional indicator is not necessary.
Complex formation evaluations or complexometries
They are based on the reaction of formation of a complex between the analyte and the titrant. The chelating agent EDTA is widely used to titrate dissolving metal ions. These valuations generally require specialized indicators that form weaker complexes with the analyte. An example is Eriochrome Black T for titration of calcium , magnesium or copper (II) ions .
Precipitation Ratings
They are based on precipitation reactions. One of the most common types are Argentometries: precipitation of anions such as halogens (F-, Cl-, Br-, I-) and thiocyanate (SCN-) with the silver ion . Ag +. This qualification is limited by the lack of appropriate indicators.
Laboratory supplies
In the procedure used to perform the titration or titration the following are used:
- Burette
- Test tube
- Volumetric pipette
- 5 and 10 ml pipettes
- 50 and 250 ml beakers
- Test tubes
- 200 ml balloons.
