Complexometric titrations are used for the determination of metal ions.
These occurs where Covalent Bonds are formed i.e., sharing of electrons occur. These metals will not ionize like in Acid-Base Titrations.
Diagram explains the presence of :
EDTA or Ethylenediaminetetraaceticacid in the burette.
EDTA is a ;
1.) Complexing agent
2.) Chelate i.e., a compound containing a ligand (typically organic) bonded to a central metal atom at two or more points.
Here the EDTA is joined with a Metal (M) ion by 2 coordinate bonds.
3.) Ligand
4.) Sequestering agent is a dyeing auxiliaries which is used during dyeing for removing hardness of water.Sequestering agents combine with calcium and magnesium ions and other heavy metal ions in hard water. They form molecules in which the ions are held so securely (sequestered) that they can no longer react.
COMPLEXOMETRIC TITRATION TAKES PLACE AS FOLLOWS :
- When EDTA is added into the conical flask, the metal forms covalent bond with the complexing agent (EDTA).
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