N A Ramaiah
Articles written in Proceedings – Section A
Volume 43 Issue 5 May 1956 pp 286-296
Decomposition of murexide in solutions of low pH (2–6) has been investigated spectrophotometrically. At pH<6, the characteristic absorption of of murexide at λ=530 mμ decreased irreversibly with time, following first order law; the corresponding rate constant
Volume 43 Issue 5 May 1956 pp 297-305
Reduction of murexide at the dropping mercury electrode was investigated. Data obtained at different concentrations in the range 0·5-2 mM showed that the half-wave potential of murexide was −0·38 volt
Volume 44 Issue 1 July 1956 pp 26-35
Alternating and direct current polarograms of Cd++ at different concentrations in the range 0·1 to 10 mM were recorded using 0·1 M potassium chloride solution as the supporting electrolyte. While the diffusion current id in dc polarography increased linearly with concentrations up to 10 mM, the summit current is at - 0·62 volts vs. S.C.E. (the half-wave potential of Cd++) increased linearly up to 1 mM tending to saturate at larger concentrations. The potential width of the ac peaks was lower than the corresponding dc wave-spread indicating that analysis of a mixture of two components with their half-wave potentials close to each other, was possible in the ac polarography.
Volume 44 Issue 1 July 1956 pp 46-52
The decomposition of murexide in acidic solutions was studied spectro-photometrically employing different strong acids like HC1, HBr and HNO3 and mixtures of these acids and neutral salts like KCl, KBr, KI and KNO3. The velocity constant k appeared to be a linear function of the concentration C of the strong acid used, and obeyed a relationship:
Volume 44 Issue 2 August 1956 pp 83-89
Alternating and direct current polarograms of cadmium were recorded at different pH values in the range 1–12. At pH < 11, cadmium was reduced reversibly at the dropping mercury electrode, giving well-defined waves on both ac. and dc. polarography. The wave-width of ac. polarograms was less than that of dc. polarograms in the entire range of pH studied.
Volume 44 Issue 2 August 1956 pp 90-95
Absorption spectra of 4-(
Volume 44 Issue 3 September 1956 pp 134-138
The composition of cadmium ferrocyanide complex was investigated polarographically using KCl, KBr, KNO3, (NH4)2SO4, K2SO4 and NH4Cl as the supporting electrolytes. Amperometric titrations indicated that the composition of precipitated complex was Cd5K6 [Fe (CN)6]4. The results showed the possibility of amperometric estimation of Cd++ by Fe (CN)6-4 within an error 1 per cent.
Volume 45 Issue 2 February 1957 pp 97-104
Volume 45 Issue 2 February 1957 pp 113-116
Employing the absorption at λ=630 mμ of copper ammonium complex, a new method for determination of Cu++ by sodium versenate was described. The experimental error involved in the method was less than 1%.
Volume 51 Issue 4 April 1960 pp 177-188
Dissociation of gallic acid at different temperatures in the range 300–380 Å was investigated using glass and calomel electrodes. Applying modified Debye-Huckel equation the thermodynamic dissociation constant
Volume 52 Issue 5 November 1960 pp 197-208
Conductance measurements of murexide or ammonium purpurate solutions were made at 30° + 0.05°C. using a Serfass conductivity bridge. Ostwald’s dilution law was found to be inapplicable; equivalent conductance at infinite dilution and the classical and thermodynamic dissociation constants were computed by various methods applicable for systems involving ion association. The following physico-chemical constants of murexide were calculated :-
Thermodynamic dissociation constant.
Ionic mobility of purpurate ion.