M R A Rao
Articles written in Proceedings – Section A
Volume 34 Issue 5 November 1951 pp 324-328
1. The effect of pH and of wetting agents on the adsorption of crystal violet at the surface of glass has been investigated.
2. At low pH values, a wetting agent at first increases the adsorption of the dye. But with an increase in the concentration of the wetting agent the adsorption falls off rapidly and drops almost to zero. At higher pH values the wetting agent diminishes increased adsorption of the dye. An explanation has been offered to account for these observations.
Volume 34 Issue 5 November 1951 pp 329-334
1. In presence of Igepon T, the pH of solutions, as measured colorimetrically with thymol blue and bromophenol blue as indicators, is found to be lower in value than that obtained with the glass electrode. The value of — Δ pH (pH by the glass electrode — pH by the colorimetric method) is found to be influenced by the presence of salts like sodium chloride, sodium sulphate and calcium chloride.
2. With thymol blue, an increase in salt concentration diminishes the value of — Δ pH, while with bromophenol blue the opposite effect is observed.
3. With calcium chloride, the effect of salt concentration on — Δ pH is far more pronounced than with sodium chloride.
4. The results are explained on the basis of the effect of the salts on zeta potential, in relation to the formation of complexes by the acidic and the basic forms of the indicator, with the wetting agent.
Volume 35 Issue 3 March 1952 pp 136-144
1. A new method for the determination of variation of interfacial and surface tensions with time, has been described. In this method, the advantages of the pendant drop method are combined with those of the drop weight method, thus simplifying the experimental technique.
2. Variation of interfacial and surface tenssions with time has been investigated for congorubin solutions. The rubin solution yields at the air-liquid interface a solid film and at the solution-benzene interface a gaseous type of film.
3. The effect of concentration of rubin on the variation of interfacial tension with time has been studied. At concentrations of rubin higher than 0·005% the fall in the interfacial tension will be large.
4. Salts like sodium chloride and potassium iodide lower considerably the interfacial tension between rubin solution and benzene. Lowering of pH also brings about a fall in interfacial tension.
5. The slow variation of interfacial tension has been accounted for, on the basis of changes in zeta-potential.
Volume 35 Issue 4 April 1952 pp 194-201
Volume 43 Issue 4 April 1956 pp 213-219
The reaction of hydrated ceric oxide with hydrogen chloride in methyl alcohol under controlled conditions did not result in the isolation of hexachloroceric acid.
Hexachloroceric acid has been obtained as a crystalline product from the reaction of hydrated ceric oxide and hydrogen chloride in dioxane.
Conditions have been worked out for obtaining the crystals in a pure form. Analytical results agree with the formula H2CeCl6, 4 C4H8O2. It has not been possible to obtain the acid without the dioxane of solvation.
The pyridinium salt of the acid has been prepared, the analytical values agree with the formula (C5H5NH)2CeCl6 for the complex.
Volume 43 Issue 5 May 1956 pp 265-271
A solvent is not necessary for the reaction of hydrogen chloride with hydrated ceric oxide to form hexachloroceric acid. The product of reaction is stable at low temperatures. Under optimum conditions, the percentage of hydrochloroceric acid produced was about 60.
Volume 48 Issue 6 December 1958 pp 317-323
Suitable conditions for preserving hexachloroceric acid crystals without decomposition have been found out from stability studies under various conditions. From studies on spectral characteristics and electrical conductivity in dioxan and methyl alcohol solutions, a mode of dissociation has been postulated.
Volume 57 Issue 6 June 1963 pp 315-329
Volume 60 Issue 1 July 1964 pp 31-35
The standard heats of combustion of the disubstituted ureas, N, N′-diheptyl urea, N, N′-dioctyl urea and N, N′-didecyl urea and the carbamates,