The oscillatory reaction between potassium bromate and gallic acid (in presence of sulfuric acid and ferroin indicator) has been calorimetrically and potentiometrically studied in binary mixtures of water and organic solvents viz. dimethyl formamide, acetonitrile, tetrahydrofuran and 1,4-dioxan. The effects of solvent polarity, stirring condition, indicator concentration, aerial oxygen and chloride ion on the oscillatory process have been examined. The oscillatory behaviour of the reaction probed by the potentiometric method has a general agreement with the calorimetric method. An attempt has been made to determine the order of the Fe 2+ Fe 3+ oxidation reaction. The damping coefficients of the oscillatory process in aqueous and mixed solvent media have been estimated. © by Oldenbourg Wissenschaftsverlag, München.

K MUKHERJEE

D C MUKHERJEE

Fulltext

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Zeitschrift fur Physikalische Chemie

Oscillatory reaction of bromate-gallic acid. A calorimetric and electrometric study in aquo-organic solvent media

Thermal oscillations in oxalic acid-bromate-MnSO4-H2SO4-acetone system have been studied in aqueous solution of nonionic surfactants, TX-100, Tweens (20, 40, and 60), and Brijs (56, 58 and 76). It has been observed that significantly low concentration of the surfactants can inhibit the oscillatory reaction. In general, they have inhibitory effects on the frequency and enthalpy of oscillations. The inhibition has been found to have direct dependence on the length of the nonpolar tail of the surfactant molecule. There is a threshold concentration for a surfactant above which oscillation stops, and this threshold or critical concentration decreases with increasing length of the surfactant chain. The amphiphile -heptanol has also shown significant inhibitory effect. © 2001 American Chemical Society.

Journal of Physical Chemistry A

Belousov-zhabotinsky oscillations in bromate-oxalic acid-MnSO4-H2so4-acetone system in nonionic surfactant medium. A calorimetric study

The oscillatory reaction between potassium bromate and gallic acid in sulfuric acid medium has been studied calorimetrically with and without ferroin indicator. Enthalpy changes during oscillations have increased with increasing bromate concentration in presence and absence of the indicator. Prominent catalytic activity of the indicator has been observed. An initial large enthalpy change has been observed in both uncatalyzed and catalyzed conditions prior to the starting of oscillation. Attempts have been made to correlate the main thermal events with the proposed mechanism of the reaction. © 1995 John Wiley & Sons, Inc. Copyright © 1995 John Wiley & Sons, Inc.

International Journal of Chemical Kinetics

Temperature oscillations in bromateâ€“gallic acid system: A calorimetric study

Certain novel features of the Belousov-Zhabotinsky (B-Z) system employing different mixed substrates and Mn(II) as the catalyst are presented. Malic acid is the common substrate together with one of malonic, citric, cyanoacetic, maleic, acetic, oxalic, or tartaric acid as the second substrate. The correlation of the oscillatory behaviour with values of exchange current density establishes the oscillatory control by the redox couple, namely, Mn(III)/Mn(II) and (or) Br2/Br-. Each substrate when used alone gives rise to an oscillatory behaviour with characteristic features that can be compared with the system containing mixed substrate. The combination of substrates provides different modes of oscillatory behaviour such as entrainment, independent, partial inhibition, or complete inhibition. These observations are rationalized in terms of relevant steps involved in the mechanism of the reaction.

Canadian Journal of Chemistry

Novel experimental findings in the B-Z system employing mixed substrates

The oscillatory behaviour of the Belousov-Zhabotinsky system with Ce(III) as the catalyst and citric, malic and malonic acids as the substrate individually or two together is presented and discussed. The behaviour of the system is modified by the inclusion of the second substrate leading to entrainment, independent, reinforcememt or entrainment with reinforcement. The behaviour of the system with individual and mixed substrates can be understood in terms of the individual steps involved in the mechanism of the overall reaction. © 1995.

Journal	Zeitschrift fur Physikalische Chemie
Publisher	Oldenbourg Wissenschaftsverlag GmbH
ISSN	0942-9352