Thermodynamic Properties of Aqueous Organic Solutes in Relation to Their Structure. Part I. Free Energy of Transfer from H₂O to D₂O for a Series of Isomeric Ketones

Abstract

The solubilities of 18 decanones have been measured in H 2 0 and D 2 0 at 25°C from their U.V. absorption spectra. The data were used to calculate AG,O, the standard free energy of transfer of these solutes from H 2 0 to D,O. AG,O was found negative for the saturated ketones, but positive for most of the unsaturated and polycyclic isomers. A rough correlation was observed between AG,O and the degree of branching in the hydrocarbon chains of the ketones: AG,O increases with the degree of branching. From the temperature dependence of AG,D obtained at 10, 25, and 40 "C, heats of transfer AH? were determined for typical ketones, namely 2-decanone and adamantanone. AH? was found as -2.1 kcal mol-' for 2-decanone and -0 + 0.5 kcal mol-' for adamantanone.The results are discussed in terms of two main contributions: (I) an isotope effect in the free energy of cavity formation and (2) L'interpretation des resultats est donnee selon deux contributions principales aux fonctions de transfert: (1) difference dans I'tnergitique de la formation d'une cavite dans les deux solvants et (2) difference dans les effets que les solutes exercent sur la structure des solvants. La premiere contribution est evaluee a I'aide de la theorie "scaled-particle", et la specificit6 observee dans le AGP des differents solutes est attribuee i la partie structurale de la fonction de transfert.

Transport properties of aqueous electrolyte solutions. Temperature and concentration dependence of the conductance and viscosity of concentrated solutions of tetraalkylammonium bromides, ammonium bromide, and lithium bromide

“…of these terms is, in general, ambiguous because little is known about the structure being broken and/or made. However, these classifications are in agreement with thermodynamic data.13 **" 21 For concentrated aqueous solutions there are no adequate theories of conductance and viscosity. Existing hydrodynamic theories1•2,22"25 are rarely valid at concen-trations greater than 0.1 M. The equation of Robinson et &\ 25,26 = a2c1/2 1 t B1FCV* ]/,o\ (1 + BáC1/2) J [ (1 + BáC1/2) Jv V ) (1) has been found to represent the conductivity of completely dissociated electrolytes up to 6 M. In this equation Bx = 8.20 X 105/(cT)3/2, B2 = 82.5/tj(eT)1/2, BáC1/2 = SO^OáC1/2/^?…”

“…[13][14][15][16][17][18][19][20][21] For Concentrated aqueous solutions there are no adequate theories of conductance and viscosity. Similar classification of ions as water-structure breakers and waterstructure makers have been made re~ently.l'-~~ The use of these terms is, in general, ambiguous because little is known about the structure being broken and/or made.…”

Thermodynamic properties of aqueous organic solutes in relation to their structure. Part III. Apparent molal volumes and heat capacities of low molecular weight alcohols and polyols at 25 °C

“…The alcohols were chosen so as t o emphasize the effects of (1) increasing the length of the hydrocarbon residue, (2) branching of this alkyl residue, and (3) addition of other hydroxy groups in several typical molecules. The study of polyols presents obvious interest in Can.…”

Enthalpies of interaction of aliphatic ketones with polar and nonpolar solvents

“…Heats of vaporization for 2-decanone, 2-undecanone, and 6undecanone have not previously been measured, and conflicting values have been reported for several other ketones (Table II). We have therefore chosen to measure heats of vaporization (AHV) of 12 of the C5-C11 ketones of interest, using a recently developed GC-calorimetry method.15 The previously unmeasured value for the hydrocarbon 2,2,4,4-tetramethylpentane was also determined (Table III). This technique requires values of ACP [Cp{ 1) -Cp(g)].…”