Heat capacities and volumes of some non-electrolytes in N,N-dimethylformamide at 298.15 K

1987 ◽  
Vol 65 (12) ◽  
pp. 2810-2814 ◽  
Author(s):  
Henryk Piekarski
Keyword(s):  
Ethylene Glycol ◽  
Heat Capacities ◽  
Scaled Particle Theory ◽  
Partial Molal Volume ◽  
Cavity Formation ◽  
Particle Theory ◽  
Molal Volume ◽  
Analogous Data ◽  
Other Substances ◽  
Apparent Molal Heat Capacities

Heat capacities and densities of dilute solutions of formamide, acetone, tetrahydrofuran, ethylene glycol, 2-methoxyethanol, and 2-ethoxyethanol in N,N-dimethylformamide were determined at 298.15 K. Apparent molal heat capacities and volumes for these solutes in DMF were calculated and compared with the analogous data for other substances in DMF solution as well as with the data concerning solutions in methanol and water. Heat capacities of cavity formation (ΔCcav) in DMF were calculated on the basis of the Scaled Particle Theory. ΔCcav appeared to be linearly correlated with the standard partial molal volume of corresponding solutes in DMF. Similar dependences were also found for aqueous and methanolic solutions of the non-electrolytes.

scholarly journals Use of scaled-particle theory in the assessment of the Ph4As+/Ph4B− assumption for single ions

1979 ◽  
Vol 57 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Michael H. Abraham ◽  
Asadollah Nasehzadeh
Keyword(s):  
Free Energy ◽  
Recent Work ◽  
Scaled Particle Theory ◽  
Cavity Formation ◽  
Energy Term ◽  
Free Energies ◽  
Particle Theory ◽  
Novel Method ◽  
Energy Of Interaction ◽  
Solvent Molecules

A novel method for the assessment of the Ph4As+/Ph4B− assumption for free energies of transfer of single ions has recently been suggested by Treiner, and used by him to deduce that the assumption is not valid for transfers between water, propylene carbonate, sulpholane, dimethylsulphoxide, N-methyl-2-pyrrolidone, and perhaps also dimethylformamide. The basis of the method is the estimation of the free energy of cavity formation by scaled-particle theory, together with the hypothesis that the free energy of interaction of Ph4As+ (or Ph4B−) with solvent molecules is the same in all solvents, ΔGt0(int) = 0. It is shown in the present paper that (a) whether or not the Ph4As+/Ph4B− assumption applies to transfer to a given solvent depends on which other solvent is taken as the reference solvent in Treiner's method, (b) the calculation of the cavity free energy term by scaled-particle theory and by the theory of Sinanoglu – Reisse – Moura Ramos (SRMR) yields values so different that the method cannot be considered reliable, (c) the calculation of cavity enthalpies and entropies for Ph4As+ or Ph4B− by scaled-particle theory yields results that are chemically not reasonable, (d) the hypothesis that ΔGt0(int) = 0 conflicts with SRMR theory, and (e) the conclusions reached by Treiner are not in accord with recent work that in general supports the Ph4As+/Ph4B− assumption for solvents that are rejected by Treiner.

Enthalpies, heat capacities, and volumes of transfer of the tetrabutylammonium ion from water to aqueous mixed solvents from the point of view of the scaled-particle theory

1976 ◽  
Vol 54 (23) ◽  
pp. 3800-3808 ◽  
Author(s):  
Nicole Desrosiers ◽  
Jacques E. Desnoyers
Keyword(s):  
Mixed Solvents ◽  
Butyl Alcohol ◽  
Heat Capacities ◽  
Point Of View ◽  
Scaled Particle Theory ◽  
Particle Theory ◽  
Tert Butyl ◽  
Tetrabutylammonium Ion ◽  
Tert Butyl Alcohol ◽  
Alcohol Water

The enthalpies, heat capacities, and volumes of transfer of the tetrabutylammonium ion from water to urea–water, tert-butyl alcohol–water, and sodium chloride–water mixtures have been calculated at 25 °C using the scaled-particle theory. In general, the signs, magnitudes, and overall trends in the cosolvent concentration dependence of the properties are predicted from the cavity contributions only. These calculations are found to be very sensitive to the diameters chosen for the various species.For these calculations it was necessary to measure with a dilatometer the coefficients of thermal expansion of tert-butyl alcohol–water mixtures as a function of concentration and temperature.

Enthalpies and heat capacities of solution for tert-butyl chloride and bromide in alcohols. Application of SPT, SRMR, and MS

1987 ◽  
Vol 65 (7) ◽  
pp. 1474-1478 ◽  
Author(s):  
R. M. C. Gonçalves ◽  
A. M. N. Simões
Keyword(s):  
Infinite Dilution ◽  
Heat Capacities ◽  
Scaled Particle Theory ◽  
Butyl Chloride ◽  
Particle Theory ◽  
Solvent Interactions ◽  
Tert Butyl ◽  
Tert Butyl Chloride ◽  
Solvent Solvent ◽  
Enthalpies Of Solvation

Enthalpies and heat capacities of solution at infinite dilution for tert-butyl chloride and bromide in several alcohols are reported at 30, 35, and 40 °C.The Scaled Particle Theory (SPT), the Sinanoglu, Reiss, and Moura Ramos (SRMR) and the Model Solute (MS) methods were applied to the enthalpies of solvation. Significant differences in the results calculated from these theories were analysed and data discussed in terms of solute–solvent–solvent interactions.

Evaluation of thermodynamic functions relative to cavity formation in liquids: uses and misuses of Scaled Particle Theory

1981 ◽  
Vol 59 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Nicole Morel-Desrosiers ◽  
Jean-Pierre Morel
Keyword(s):  
Experimental Data ◽  
Enthalpy Of Formation ◽  
Thermodynamic Functions ◽  
Enthalpy Of Vaporization ◽  
The Other ◽  
Scaled Particle Theory ◽  
Cavity Formation ◽  
Particle Theory ◽  
The Enthalpy Of Formation ◽  
Good Agreement

The Scaled Particle Theory (SPT) is probably the most powerful theory presently available, that enables the calculation of the thermodynamic functions relative to the formation of cavities in liquids. We give the general relationship between the enthalpy of vaporization and the enthalpy of formation of a molecular cavity in a pure normal liquid; the good agreement with the experimental data constitutes one of the strongest arguments justifying the application of SPT to real liquids. However, we show that SPT can lead to uncertain cavity terms if the molecular diameters of the studied liquids are not well-known. We compare, on the other hand, the cavity terms (G and H) calculated from Sinanoglu's theory, since this theory has been used to that end recently, with those obtained from SPT.

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