Potassium Permanganate In Presence Research Articles

Notes on the manganese determination

A weakly acid manganese sulfate sample is precipitated with freshly filtered potassium permanganate in presence of sodium acetate and zinc sulfate. The manganese oxide precipitate is separated from the bulk of interfering elements by filtration, dissolved with ascorbic acid, and titrated with EDTA to an Eriochrome Black T or Thymolphthalexon end point. Zinc, cadmium, copper, nickel, and mercury are masked with potassium cyanide; iron and aluminum with triethanolamine. Since the iron-triethanolamine complex is colored, an indirect titration is performed in this case.

Ignitability of nonhypergolic propellants in presence of potassium permanganate

Ignitability of nonhypergolic propellants in presence of potassium permanganate

ピペラジン類の合成研究 (第15報)

Oxidation of 2, 3-dimethylpyrazine with potassium permanganate afforded 3-methylpyrazine-2-carboxylic acid but not pyrazine-2, 3-dicarboxylic acid. Further permanganate oxidation of 3-methylpyrazine-2-carboxylic acid afforded the 2, 3-dicarboxylic acid, though in an extremely poor yield. 3-Methylpyrazine-2-carboxylic acid was also obtained by electrolytic oxidation in the presence of potassium permanganate. Copper, nickel and lead were used as the electrode. There was no great increase in the yield in spite of changes in electrolytic conditions such as the kind of electrode used, current density, reaction of the solution, and temperature.

Oxidations with potassium permanganate in presence of fluoride : Potentiometric titration of mercury(I) and the redox potential of the Mn +7/Mn +3 system

Mercury(I) can be titrated potentiometrically with permanganate in the presence of fluoride and sulphuric acid The optimum conditions are 2.5– 10 ml of 9 N acid and 10–100 ml of 2% sodium fluoride at a tempeiature of 25–40° Larger amounts can be determined than in the visual method, although copper (II) is a suitable indicator screen in the titration of fairly large amounts The reverse titration is also satisfactory, the optimum conditions are 1.5–4 ml of 9 N acid and 25–75 ml of 2% fluoride at 25–40°. The formal redox potential of the Mn +7/Mn +3 couple is 14 V, in piesence of 1.38 N H 2S0 4 and 0 12 N NaF

Direct titration of mercury (i) with potassium permanganate

Mercurous solutions can bc successfully titrated with potassium permanganate in presence of 0.5–1 N H 2SO 4 and 1–1.5% NaF at 35–50°C, Sharp end-points arc obtained when the maximum concentration of monovalent mercury after mixing with the other reagents is 0.005 N. At higher concentrations the reaction is sluggish and, the end-points arc not sharp.

Quinoxalineの電解酸化による2,3-Pyrazinedicarboxylic Acidの製造

Preparation of 2, 3-pyrazinedicarboxylic acid by electrolytic oxidation of quinoxaline, in the presence of potassium permanganate was studied, using a diaphragm. The most suitable electrode material, optimal concentration of the alkali, amount of permanganate added, electric density, electrolytic temperature, manner of quinoxaline addition, and amount of electricity were determined.

The Estimation of Tannin in Cider

The method at present in use for the estimation of tannin in apple juice and cider is that used by Lloyd. It is a modification according to Kraus of Löwenthal's method, and consists in titrating the cider directly with potassium permanganate in presence of indigo as an indicator. The permanganate is standardized by means of “pure tannin,” it being assumed that both this and the tannin present in the apple are digallic acid, and have the composition C14H10O9. It is apparent that all the permanganate reducing substances present in the cider will be included in the tannin content; moreover the amount of indigo used is not sufficient to retard noticeably the oxidation of the non-tannins for which purpose it was originally used in Löwenthal's method. The results obtained by this method are therefore only comparative.

The titration of oxalic acid by potassium permanganate in presence of hydrochloric acid

The titration of oxalic acid by potassium permanganate in presence of hydrochloric acid