Complexometric titration (sometimes chelatometry) is a form of volumetric analysis in which the formation of a colored complex is used to indicate the end point of a titration.  Complexometric titrations are particularly useful for the determination of a mixture of different metal ions in solution.  An indicator capable of producing an unambiguous color change is usually used to detect  the end-point of the titration. Complexometric titration are those reactions where a simple ion is transformed into a complex ion and the equivalence point is determined by using metal indicators or electrometrically.