![4. Complexometric titration
Complexometric titration 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.
Complex is formed by the reaction of metal ion (Mn2+)with either an anion
e.g.[Ag(CN)2]+ or neutral molecule e.g. [Ag(NH3)2]+
Ag+ +2CN- [Ag(CN)2]-
Ag++2NH3 [Ag(NH3)2]+](https://image.slidesharecdn.com/whichtitrationtechniqueisbestfittodetectwhattypeofanalyte-201107151119/85/Which-titration-technique-is-best-fit-to-detect-what-type-of-analyte-7-320.jpg)
Which titration technique is best fit to detect what type of analyte?
- 1. Presentation on Which titration technique is best fit to detect what type of analyte. Presented By: Zubayar Rahman Department of Pharmacy University of Asia Pacific
- 2. Titration: The act of adding standard solution in small quantities to the test solution till the reaction is complete is termed titration. The basis of this process is the reaction between the analyte and solution of known concentration(titrant). The analyte is taken in a conical flask using a pipette and the standard solution of known concentration is taken in a calibrated burette. Titration are such type: 1.Acid-base titration. 2.Redox titration. 3.Amperometric titration. 4.Complexometic titration. 5.Potentiometric titration.
- 3. 1. Acid-base titration Acid-Base titrations are usually used to find the amount of a known acidic or basic substance through acid base reactions. The analyte is the solution with an unknown molarity. The reagent is the solution with a known molarity that will react with the analyte. An indicator is used to determine the end point of the reaction. Acid + Base Salt + Water
- 4. (A). Aqueous acid base titration When acid or base is dissolved in water HCl+NaOH Strong acid- strong base CH3COOOH+NaOH Weak acid- strong base HCl+NH3 Strong acid- weak base CH3COOH+NH3 Weak acid- weak base (B). Non-aqueous acid base titration Non-aqueous acid base titrations are the titration in which weakly acidic or weakly basic substances are titrated using non-aqueous solvents to get sharp end point. It is suitable for the titration of very weak acids and very weak bases where it provides a solvent in which organic compounds are soluble.
- 5. 2. Redox titration A redox titration is a type of titration based on a redox reaction between the analyte and titrant. Redox titration may involve the use of a redox indicator and/or a potentiometer. A common example of a redox titration is treating a solution of iodine with a reducing agent to produce iodide using a starch indicator to help detect the endpoint. Iodine (I2) can be reduced to iodide (I−) by e.g. thiosulfate (S2O3 2-), and when all iodine is spent the blue colour disappears.
- 6. 3. Amperomatric titration The detection of ions presence on solution on the basis of electric current or change in electric current is called as Amperometry. For example, for the detection of chlorine can be carried out by using amperomerty. When chlorine is added to water it hydrolyzes and forms HOCl which further dissociates into respective ions. Cl2 + H2O → HOCl + H+ + Cl- HOCl (aq) → OCl- (aq) + H+ (aq) In an amperometric method for the detection of chlorine a fixed voltage applied between two electrodes whereas the reaction takes place at the working electrode that is cathode and reduction of chlorine (HOCl) back to chloride (Cl-) takes place and chlorine generate at the anode. Since, the current flow in amperometric sensor is due to chlorine, hence the amount of current flow is directly proportional of chlorine presented to the sensor.
- 7. 4. Complexometric titration Complexometric titration 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. Complex is formed by the reaction of metal ion (Mn2+)with either an anion e.g.[Ag(CN)2]+ or neutral molecule e.g. [Ag(NH3)2]+ Ag+ +2CN- [Ag(CN)2]- Ag++2NH3 [Ag(NH3)2]+
- 8. 5. Potentiometric titration Potentiometry is the field of electro analytical chemistry in which potential is measured under the condition of no current flow. Or Potentiometry is one of the volumetric technique of electro-analytical chemistry. Or Potentiometry is the method used in electroanalytical chemistry usually to find the concentration of solute in solution in potentiometric measurement the potential between two electrode is measured using the high impedance voltmeter. Potentiometric titration is used in Clinical chemistry. Environmental chemistry. Agriculture field. Detergent manufacturing. Etc.