• Shirish D Pradhan

      Articles written in Journal of Chemical Sciences

    • The chain length and isomeric effect of alcohol on the excess properties of amine-alcohol systems: Excess free energy of mixing, enthalpy of mixing and volume change on mixing

      Shirish D Pradhan

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      The effect of change in alkyl chain and the branching of the alkyl chain of alcohol on the interactions with amine has been studied. For this purpose, the three excess properties, viz., free energy of mixing, enthalpy of mixing and volume change on mixing have been studied. The vapour liquid equilibrium ofn-butylamine 1-propanol,-1-butanol,-2-propanol,-2-butanol systems were studied at 55°C The four systems show negative deviation from Raoult’s Law. The heats of mixing ofn-butylamine with 2-propanol and 2-butanol determined at 25°C show that both the systems are strongly exothermic because of amine-alcohol complex formation. The volume change on mixing of the four earlier mentioned systems were determined at 25°C, and is found to be negative for all the four systems, with the maxima at 0·5 mol fraction. Increase in the alkyl chain length of alcohol does not change the excess properties while the branching of the alkyl chain considerably affects all the excess properties.

    • Calorimetric study of isomeric and steric effects amine-alcohol interactions

      Shirish D Pradhan Gopal Pathak

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      The enthalpy of complex formation between different isomers of butylamine and butylalcohol was determined at 30°C by obtaining the partial molar enthalpy of dissociation of 1∶1 complexes inn-hexane. In both seriesviz. normal amine with isomeric alcohols and normal alcohol with isomeric amines, the enthalpy of complex formation showed the same trend ast>n>iso>sec.

      The trend in normal-normal, normal-tertiary, tertiary-tertiary and secondary-secondary omplexes was ast−n>n−n>t−t> sec-sec. Both these trends were explained in terms of steric and electromeric effects.

    • Enthalpies of complex formation of dibutyl and tributyl amines with isomeric butanols

      Shirish D Pradhan Gopal Pathak

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      Enthalpies of complex formation (ΔHc) of dibutyl and tributyl amines with the four isomeric butanols were determined at 30°C. The present data were compared with the previous data on isomeric butanols with monobutyl amine complexes. The ΔHc in the case ofn-alcohol has been found to decrease by about 4·0±0·4 kJ/mole on replacement of each hydrogen atom of the NH2 group. The branching of the butyl chain, also, decreases the strength of the complex due to steric hindrance.

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