Redox titration is a type of titration that involves the oxidation (loss of electrons) and reduction (gain of electrons) of a specific substance in a solution. In this type of titration, the redox reaction occurs between the analyte (substance being analyzed) and a reagent (substance added to the analyte) that has a known reduction or oxidation potential.
The goal of redox titration is to determine the concentration of the analyte in the solution by measuring the amount of reagent required to reach a specific endpoint. The endpoint is determined by a change in the color, pH, or potential of the solution.
There are different types of redox titration, depending on the substances involved. For example, the most common types are iodimetry, permanganometry, and dichrometry.
Iodimetry involves the use of iodine (I2) as the reagent and thiosulfate as the titrant. The endpoint is reached when all the iodine has reacted with the analyte and the excess unreacted iodine is detected by a starch indicator that turns the solution blue-black.
Permanganometry uses potassium permanganate (KMnO4) as the reagent and oxalic acid as the analyte. The endpoint is reached when the pink color of the permanganate disappears and turns colorless.
Dichrometry uses potassium dichromate (K2Cr2O7) as the reagent and iron as the analyte. The endpoint is reached when all the iron has reacted with the dichromate, and the color changes from orange to green.
Redox titration is a crucial technique used in analytical chemistry as it enables the determination of concentrations of certain chemical species.