What is volhard titration?
: a method for the determination of chlorine, bromine, and iodine in the form of halides by precipitating them with excess silver nitrate and titrating the excess with a thiocyanate solution.
What is volhard method and its uses?
The volhard method is a procedure for titrating silver(I) with standard potassium thiocyanate (KSCN). The titration is carried out in acidic solution. The method is widely used for silver and chloride, because the titration can be done in an acidic solution.
What is advantage of volhard method?
ADVANTAGES OF VOLHARD’S METHOD This method is useful where the titrations have to be performed at low pH. The strong acidic environment give advantage for halide analysis because ions like carbonate, oxalate and arsenate do not interfere. Give accurate results due to back titration.
Why is the volhard method performed in an acidic system?
The titration must be carried out in an acidic solution to prevent the precipitation of Fe3+ as Fe(OH)3. The Volhard method was first published in 1874 by Jacob Volhard. Before the end point, the precipitate of AgCl has a negative surface charge due to the adsorption of excess Cl–.
Why Volhard method is back titration?
The titration will be carried out in acidic medium for use of nitric acid in this Titration it should be free of anides of Nitrogen. The volhard method is used to determine the concentration of Ag ion or concentration of halide ions indirect titration ( Back Titration).
What is the example of self indicator?
A best example of self-indicator is potassium permanganate which plays as self-indicator in oxidation reduction titration by disappearing or again showing its pink color while the reaction is finished.
What is Mohr’s method?
This method determines the chloride ion concentration of a solution by titration with silver nitrate. As the silver nitrate solution is slowly added, a precipitate of silver chloride forms. Ag+(aq) + Cl–(aq) → AgCl(s) The end point of the titration occurs when all the chloride ions are precipitated.
What is Fajans method?
Fajan’s method :- The precipitation titration in which silver ion is titrated with Halide or thiocyanate ions in presence of adsorption indicator is called as fajan’s method. The indicator which is a dye existing in solution as the ionized from usually anion .
What is the principle of Fajans method?
In the Fajans method, named after Kazimierz Fajans, typically dichlorofluorescein is used as an indicator; the end-point is marked by the green suspension turning pink. Prior to the end-point of the titration, chloride ions remain in excess. They adsorb on the AgCl surface, imparting a negative charge to the particles.
Is KMnO4 a self indicator?
Potassium Permanganate is a flexible and potent oxidant which can be used by overt or indirect titration to classify many compounds. A special value of Potassium Permanganate is that it acts as an indicator of its own.