Browsing by Author "Asha Varma"

Now showing 1 - 2 of 2

Amperometric ascorbimetric determination of cerium(IV) and Iron(III) with two polarized electrodes
(Springer-Verlag, 1961) D. Singh; Asha Varma; V.S. Agarwala
Amperometric ascorbimetric determinations of cerium(IV) and ferric iron have been carried out at 50°C with two polarized electrodes at 200 and 100 mV respectively. The results obtained are fairly accurate and precise within ±1.0 per cent. A simple method for successive determination of cerium and iron has been developed; and conditions for such estimations have been established. At an acidity of 2.5 M with respect to sulphuric acid, it is possible to ward off the reduction of ferric iron and thereby cerium(IV) is successfully titrated with ascorbic acid in this medium. After completion of the reaction and then lowering the acid concentration to pH 1.5 with aid of ammonium hydroxide, FeIII is titrated with standard ascorbic acid yielding good results. © 1961 Springer-Verlag.
Amperometric iodimetric determination of nickel(II) at constant voltage with two polarised electrodes
(Springer-Verlag, 1962) D. Singh; Asha Varma
The amperometric iodimetric determination of nickel(II) in presence of excess dimethylglyoxime in ammoniacal medium at ph 6.5, has been carried out at 30 millivolts with two polarised electrodes. The redox reaction is quantitative and the results obtained are accurate and satisfactory. The formation of complexes alters the oxidation potential of Ni2+/Ni4+ to a lower value, so as the former is titrable with iodine. The method is simple, sensitive and convenient; and has the advantage that it permits determination of trace amounts of nickel of the order of 10-4 M with fair degree of accuracy. At higher dilutions, error exceeds 5 percent. © 1962 Springer-Verlag.