Introduction: According to (Khan): A complexometric titration as defined by IUPAC as a volumetric titration where a soluble complex can be formed by titrating a metal ion with a ligand in an aqueous solution and a titrant is one of the reagents used in titration. [4]M(H2O)n + L = M(H2O)(n-1)L + H20 [4](Khan): other states, here L are the ligand and which is formed via the complete replacement of the molecules of water by other ligands can appear until the formation of the MLn complex. “n” is the coordination number of the metal ion and represents the maximum number of monodentate ligands that can be bound to it. [8]Figure 1: The hexacyanoferrate iron (III) ion: contains 6 ligands which are linked to the central metal therefore has a coordination number of 6 (n=6¬). (Hussain, 2007) [13] Complexometric titration takes place in an aqueous sample in order to displace water from the ion. As the metal ion will be ionized once in solution, empty valence shells are therefore obtained. [1] According to (Biesen), in a complexometric titration, a covalent coordination bond is formed via the ability of most metal ions to receive unshared electron pairs. from an anion or a molecule. In addition, a ligand: which is a molecule that contains a pair of free electrons and can therefore form a bond with a complex ion or a metal ion. Therefore, a ligand determines the concentration of metal ions. [2] Therefore, according to (Hussain, 2007), the maximum amount of ligands that can participate in a titration is known as the Werner number and allows the formation of complexes. [13] A complexometric titration is based on the following equations: Figure 2: Adapted from (Huss...... middle of article ......ble from: https://www.bhsu.edu/ Portals/91/AnalyticalChemistry/StudyHelp/LectureNotes/Chapter13.pdfComplexometric titrations [home page on the Internet]. /generador/sites/martinezma/archivos/EDTA.pdfGusdinar T. COMPLEXOMETRIC TITRATION A method of applying Inorganic Pharmaceutical Analysis [home page on the Internet] . Undated [cited March 20, 2014]. /download.fa.itb.ac.id/filenya/Handout%20Kuliah/Inorganic%20Pharmaceutical%20Analysis%202008. /English%20Version/05.%20COMPLEXOMETRIC%20TITRATION.pdf.EDTA Titrations [home page on the Internet]. Undated [accessed March 24, 2014].