Precipitation titrations are used to determine the concentration of a dissolved substance. The experiment is a laboratory technique to qualitatively determine the concentration of an unknown dissolved substance. In a precipitation titration, one unknown solution is added dropwise to another solution until the end point is reached.
Precipitation Titration: A laboratory technique in which one solution (called the “indicator”) is slowly added dropwise to another solution (called the “analyte”), and the mixture’s color change indicates when an endpoint has been reached.
The chemical reaction which is formed by the separation of a solid substance by the addition of two solution of different substances is called precipitation reaction.
The solid substance formed in the reaction is known as precipitate(ppt).
Titration involving the formation of ppt upon mixing the solution of two reacting species is called precipitation titration.
Theory of precipitation titration
Precipitation titrations are a type of analytical chemistry that is used to determine the concentration of an analyte.
The theory behind this type of titration is that when a reagent (usually an acid or base) is added to a solution, it will react with the analyte and form precipitates. This can be seen as a solid, liquid, or gas. The volume of precipitate formed will depend on how much analyte was in the original solution.
The precipitation of solid substance is because of its low solubility. For example, in the titration between AgNO3 and KCl, AgCl is formed which is a sparingly soluble salt.
Since, the solution of a sparingly soluble salt in always saturated, there exists a state of equilibrium between solid salt& its ion in the solution.