The acetic acid used as solvent in the titration should have a water content not exceeding 0.1 to 0.2 per cent. The perchloric acid solution (usually 0.1 N) is prepared from 70 per cent. aqueous solution, which is diluted with acetic acid. Acetic anhydride is added after the dilution to eliminate the water.
What is the role of mercuric acetate in titration reaction?
Mercuric acetate : It is essentially added to prevent the interference of the hydrochloric acid dis-placed through the formation of the relatively un-ionized HgCl2, thereby making a predominant shift in the equilibrium so that the titrimetric reaction is quantitative.
Are there any non-aqueous titrations of pharmaceuticals?
In actual practice, however, there are quite a number of non-aqueous titrations of pharmaceutical substances either in pure or in dosage forms that can be successfully performed potentiometrically. 1.2. Titration of Halogen Acid Salts of Bases
What is the purpose of the alkali error in titration?
The alkali error limits the use of the glass electrode as an indicating electrode in conjunction with alkali metal alkoxide titrants, particularly in basic solvents. Thus, the antimony-indicating electrode, though somewhat erratic, is used in such titrations.
How do you get rid of halide acid in titration?
To eliminate halide acids, the USP procedure requires the addition of excessive mercuric acetate into the sample solution, thus, producing a mercuric halide that does not interfere with the titration [2]. Generally, an excess of water is added to eliminate anhydride, however, too much water interferes with the endpoint.
Does water content in HClO4 vs titration interfere with the endpoint?
Since it has been proven that water content up to 0.5–1% in the titrate solution does not interfere with the endpoint, this amount of water in HClO 4 VS titrant, which is considered one part of the whole titration system, should not interfere either.
