The free energy of some organic substances in organic solvents

• Main Author: Harrower, Peter
• Published: University of Edinburgh 1935
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.652173

(1) x rapid and reliable method has been devised for the determination of the energy transfer of a solute from the dilute vapour (ter log p /N) or pure liquid (i.AT log p /p ?N) to a dilute solution. (2) The partial vapour pressures at low concen- trations of four lower aliphatic alcohols, some derivatives, and a few other organic compounds have been determined in benzene at 25 ?. (3) Similar determinations have been made in carbon tetrachloride. (4) with the exception of the alcohols, similar determinations have been made in cyclo hexane. (5) The energies of solvation (RT log p /N) and dilution (RP log p /p ?N) have been calculated for the solutes in benzene, carbon tetrachloride and cyclo hexane. (6) The advantage of using values of i1 log p/N as against AT log p /p ?N, for theoretical consider- ations, is demonstrated by the regularity of these values, shown in the Tables, compared with the erratic figures for tir log p /p ?N. (7) The results are interpretated in terms of Hildebrand's internal pressure theory, and show agreement with a semi -quantitative equation, based on London's equation for the mutual potential of two atoms, and Langmuir's theory of independent surface action, derived by Butler (unpublished).