Applications of Edta Titration - Kshetra K L

Applications of Edta Titration

1. APPLICATIONS OF EDTA TITRATION KSHETRA K.L 198215

2. INTRODUCTION TITRATION : is a technique in which a solution of known concentration to determine the concentration of unknown solution. types of titration : 1) Neutalaziation titration : method of using this reaction to find the amount of alkali or acid for which the concentration is not known. 2) Complexometric titration: the titration based on formation of complex ion. 3)Precipitation titration: which involves the formation of precipitates during the experiment of titration. the titrant reacts with the analyte and formes an in soluble substance . 4)oxidation reduction titration: volumetric analysis through oxidation and reduction, is based on reactions which involves the transfer of electrons from a molecules, atom or ion to another chemical species.

3. Complexometric titration Complexometric titration is a form of volumetric analysis in which the formation of coloured complex is used to indicate the end point of titration.complexomatric titrations are particularly use ful for determination of a mixture of different metal ions in a solution . Complex : metal+ligand Ligand :has a least one pair of unshared electrons avavilable for bond formation . Chelate :a chelate is produced when a metal ion coordinates with two or more donar groups of single ligand to form a five or six member hetrocyclic ring . Chelate effect : the multidentate ligand from strong 1:1 complexes with many metal ions.

4. Metal ligand complexes Complexation titration are based on the reaction of metal ion with chemical agent to form a metal-ligand complex . Complexation titration ar based on the essentially Lewis acid-base reactions, in which an electron pair is donated from one chemical to another . Ligand used in complxomeric titration are also known as chelating agents . Most chelating agent contain N or O . Elements that contain free electron pairs that may be donated to metal.

5. Difference between complexation and normal titration Complexation titration Normal titration At the end point colourful complex formation forms. Used by metal indicator and metal ion indicator. At the end point precipitate,solution may form. Normally acid base indicator can be used or sometimes it is not necessary to use indicator.

6. EDTA TITRATION EDTA ( Ethylenediaminetetraaceticacid ). one of the most common chelating agent used for complexomatric titrations in analytical chemistry . This creates the most stable metal compound . EDTA used to titrate with many elements. Ex: M n + + Y 4- = My n-4 . where M is a metal and y is the EDTA .

7. EDTA has 6 hydrogen atoms. 2 atoms form ammine group and 4 atom formes carboxylic group. so in its structure it gives free 6 electron pair that it can donate to metal ions. The four hydrogen atom are acetic. The formula of EDTA is often abbreviated H 4 Y - ,Where H 4 Represents the four acidic hydrogen atom and Y represents the remaing structure. High K f values 6 acid base sites in its structure.

8. EDTA is an example of multidentate ligand, which can bind metal multiple atoms. EDTA chelating a metal ion. EDTA is an amphoteric substance, It can donate and accept protons. At very low ph,EDTA will be present protonated from H 6 Y 2- . At very high ph,EDTA will be present in its completely deprotonated from,Y 4- .

9. Detection of the colour change The use of a metal ion indicatior in a EDTA titration can be expressed as. M – ln + EDTA M –EDTA + ln The colour change of indicator affected by hydrogen ion concentration of medium. H 2 ln Hln 2- ln 3- red blue yellow - orange

10. Types of EDTA titration Direct titration: simply an indicator to the solution of the metal ion and titrate with EDTA. Before starting the titration, it is needed to check the pH of the solution. Indirect titration : EDTA can be used as titrant for anions. Anions can be precipitated with suitable metal ion. Filter and wash the ppt with proper solution. then boil i excess EDTA to complex the metal ion. Black titration: The excess of EDTA is added to the metal ion solution and then excess od EDTA is titrated with a known concentration of a second metal ion. Displacement titration : The analyte is titrated with excess of second metal bound to EDTA.the analyte ion displaces the second metal from EDTA complex.

11. Applications of EDTA titration EDTA is able to form stable 1:1 complex ions with many different metal ions, and can therefore be used in titrations to determine the concentrations of these metal ions in the solution. QUANTITATIVE APLICATIONS: Selection and standardization of titrants: EDTA is a versatile titrant that can be used for the analysis of virtually all metal ins.although EDTA is the most commonly employed titrant for complexation titration. In the latter case, standard solutions of Ag + or Hg 2+ are used as a titrant. Organic analysis: complexometric titration continous to be listed as standard method of the determination of hardness of Ca 2+ ,CN - and Cl - and analysis of hard water.

12. Eg:ca 2+ is complicated with Mg 2+ , which also reacts with the EDTA.to prevent an interference from Mg 2+ the PH is adjusted to 12-13, using EBT as a visual indicator it gives the concentration of Ca 2+ . EDTA as alternative medicine: some alternative practitioners believe EDTA acts as an antioxidant, preventing free radicals from injuring blood vessels walls, therefore reducing atherosclerosis. eg:Detoxcream,RPI ,

13. Bio degradation of EDTA These are not only in treating hard water and waste water. in recent years, studies have demonstrated that EDTA can be degradable by specially enriched bacterial cultures .

14. References: Modern analytical chemistry- D avid Harvey. Analytical chemistry- Gaey D.Christian. https:// en.m.wikipedia .org JOSR Jurnal of dental and medical sciences,applicatios of EDTA by Mazen Doumani,adanan,Ahamad Doumani ... U S food and drug adultration:center of food safty and applied nutrition.

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