Thermodynamic properties of tetraalkylammonium halides: volumes, heat capacities, and expansibilities in H2O, D2O and urea–water mixtures from 278 to 328 K

1976 ◽  
Vol 54 (14) ◽  
pp. 2163-2183 ◽  
Author(s):  
Gérald Perron ◽  
Nicole Desrosiers ◽  
Jacques E. Desnoyers
Keyword(s):  
Transfer Functions ◽  
Heat Capacities ◽  
Excess Functions ◽  
Free Energies ◽  
Aqueous Urea ◽  
Hydrophobic Bond ◽  
Hydrophobic Solutes ◽  
Molal Volumes ◽  
The Difference ◽  
Tetraalkylammonium Halides

The densities and heat capacities per unit volume of the symmetrical tetraalkylammonium bromides (R4NBr) were measured in H2O, D2O, and 3 m aqueous urea from 0.01 to 1 mol kg−1 and from 5 to 55 °C with a flow digital densimeter and a flow microcalorimeter. Expansibilities were also measured at 25 °C for the same electrolytes in H2O and urea–water mixtures with a dilatometer. Apparent molal volumes [Formula: see text] heat capacities [Formula: see text] and expansibilities [Formula: see text] were derived. The [Formula: see text] of R4NCl and R4NI were also measured in H2O at 25 °C. The effect of urea concentration was investigated at 25 °C in the case of Bu4NBr.Once allowance is made for the anion, the properties of the larger R4N+ behave essentially as hydrophobic nonelectrolytes in water. The transfer functions from H2O to D2O have the same sign as the hydration functions and the transfer functions from H2O to urea–water mixtures the opposite sign. Whatever is the origin of the interactions giving rise to the peculiar behavior of hydrophobic R4N+ in water, these interactions are larger in D2O and smaller in the presence of urea.The excess volumes, heat capacities, and expansibilities of Bu4NBr and Pen4NBr, once corrected for the long-range Debye–Hückel interactions, all have the same sign as the hydration functions at infinite dilution, in contrast with excess free energies and enthalpies. This suggests some kind of cooperative effect as two hydrophobic solutes interact with each other without the formation of a hydrophobic bond. No conclusions can be drawn from the difference in excess functions in the various aqueous solvents.

Volumes and Heat Capacities of Transfer of Tetraalkylammonium Bromides from Water to Aqueous Urea Solutions at 25 °C

1973 ◽  
Vol 51 (2) ◽  
pp. 187-191 ◽  
Author(s):  
P. R. Philip ◽  
J. E. Desnoyers ◽  
A. Hade
Keyword(s):  
Transfer Functions ◽  
Pure Water ◽  
Heat Capacities ◽  
Tetraalkylammonium Bromides ◽  
Apparent Molal Volumes ◽  
Aqueous Urea ◽  
Molal Volumes

The apparent molal volumes and heat capacities of tetraalkylammonium bromides were measured in urea–water mixtures at 25 °C. The volumes and heat capacities of transfer from water to urea-water mixtures indicate that structural hydration effects are smaller in urea–water mixtures than in water. Also a comparison with the corresponding transfer functions from H2O to D2O suggests that urea–water mixtures are less structured than pure water.

The heat capacities and volumes of some low molecular weight amides, ketones, esters, and ethers in water over the whole solubility range

1978 ◽  
Vol 56 (22) ◽  
pp. 2808-2814 ◽  
Author(s):  
Geneviève Roux ◽  
Gérald Perron ◽  
Jacques E. Desnoyers
Keyword(s):  
Hydrophobic Interactions ◽  
Heat Capacities ◽  
Initial Slope ◽  
Pure Liquid ◽  
Factors Affecting ◽  
Solubility Range ◽  
Low Concentrations ◽  
Hydrophobic Solutes ◽  
Molal Volumes ◽  
Apparent Molal Heat Capacities

The densities and heat capacities per unit volume of aqueous solutions of propionamide, methylacetate, ethylacetate, methylethylketone and diethylketone, and bis(2-ethoxyethyl)ether were measured over the whole solubility range with a flow densimeter and a flow microcalorimeter. Most systems were studied at 10, 25, and 40 °C. Properties of the pure liquids were also measured whenever possible. The derived apparent molal volumes [Formula: see text] all decrease with concentration in the water-rich region, except with ethyl acetate which increases at high temperature. In general the more hydrophobic the solute the more negative the initial slope. All apparent molal heat capacities [Formula: see text] decrease as a function of concentration and the decrease is more important for more hydrophobic solutes. The apparent molal expansibilities [Formula: see text] are obtained from [Formula: see text]. They are positive for all solutes but, at low concentrations, they are smaller than the corresponding molar value of the pure liquid. Various factors affecting hydrophobic interactions are examined.

Volumes and Heat Capacities of Cyclic Ethers and Amines in Water and of some Electrolytes in these Mixed Aqueous Solvents

1975 ◽  
Vol 53 (17) ◽  
pp. 2591-2597 ◽  
Author(s):  
Osamu Klyohara ◽  
Gérald Perron ◽  
Jacques E. Desnoyers
Keyword(s):  
Mixed Solvent ◽  
Transfer Functions ◽  
Heat Capacities ◽  
Cyclic Ethers ◽  
Apparent Molal Volumes ◽  
Cyclic Amines ◽  
Specific Heats ◽  
Molal Volumes ◽  
Mixed Aqueous Solvents ◽  
Structural Influence

The densities and volumetric specific heats of p-dioxane, tetrahydropyran, morpholine, piperidine, and piperazine were measured in water at 25 °C with a flow densimeter and a flow microcalorimeter. The same properties were also determined for LiCl, NaCl, Me4NBr, and Bu4NBr at 0.1 m in dioxane–water, morpholine–water, and piperidine–water mixtures. The derived apparent molal volumes and heat capacities of the nonelectrolytes in water and the transfer functions of the electrolytes from water to the mixed solvent suggest that all the present cyclic amines and ethers are hydrophobic; the overall structural influence is very small with dioxane and large with piperidine.

Volumes and Heat Capacities of Dimethylsulfoxide, Acetone, and Acetamide in Water and of some Electrolytes in these Mixed Aqueous Solvents

1975 ◽  
Vol 53 (21) ◽  
pp. 3263-3268 ◽  
Author(s):  
Osamu Kiyohara ◽  
Gèrald Perron ◽  
Jacques E. Desnoyers
Keyword(s):  
Binary Mixtures ◽  
Transfer Functions ◽  
Mixed Solvents ◽  
Water Structure ◽  
Heat Capacities ◽  
Ternary Mixtures ◽  
Specific Heats ◽  
Solute Interactions ◽  
Molal Volumes ◽  
Mixed Aqueous Solvents

The densities and volumetric specific heats of binary mixtures of dimethylsulfoxide (DMSO), acetone (ACT), and acetamide (ACM) in water were measured at 25 °C with a flow densimeter and a flow microcalorimeter. The same properties were also determined for ternary mixtures of 0.1 m LiCl, NaCl, Me4NBr, and Bu4NBr in ACT–water and DMSO–water mixtures, and volumes for 0.1 m Bu4NBr in ACM–water and urea–water mixtures. The derived apparent molal volumes and heat capacities of nonelectrolytes in water and the transfer functions of the electrolytes from water to the mixed solvents suggest that, contrary to urea, the present non-electrolytes are slightly hydrophobic but, with the possible exception of ACT, their overall influence on water structure has practically no influence on the various solute–solute interactions.

Thermodynamic Properties of Aqueous Organic Solutes in Relation to their Structure. Part II. Apparent Molal Volumes and Heat Capacities of c-Alkylamine Hydrobromides in Water

1975 ◽  
Vol 53 (5) ◽  
pp. 716-722 ◽  
Author(s):  
Carmel Jolicoeur ◽  
Jeanine Boileau ◽  
Serge Bazinet ◽  
Patrick Picker
Keyword(s):  
Heat Capacities ◽  
Group Contribution ◽  
Ring Size ◽  
Solvent Structure ◽  
Apparent Molal Volumes ◽  
Molal Volumes ◽  
The Difference ◽  
Geometrical Factors ◽  
Cyclic Compounds ◽  
Methylene Group

The density and specific heat of aqueous solutions of various c-alkylamine hydrobromides, and of n-dodecylammonium bromide, have been measured at 25 °C. The limiting apparent molal volumes [Formula: see text] and heat capacities [Formula: see text] derived from these data, are compared to the corresponding quantities for n-alkylammonium and immonium salts. The methylene group contribution to[Formula: see text] and [Formula: see text] of the cyclic compounds is generally lower than that of the linear homologs; this group contribution is also found to depend markedly on ring size, in contrast to monotonous variations found in the series of the linear compounds. The difference is suggested to originate in solvation effects in which geometrical factors (solvent structure and solute geometry) play a significant role.

Apparent Molal Volumes and Heat Capacities of Tetrabutylammonium Bromide in Aqueous Electrolyte Solutions

1975 ◽  
Vol 53 (21) ◽  
pp. 3206-3210 ◽  
Author(s):  
Nicole Desrosiers ◽  
Jacques E. Desnoyers
Keyword(s):  
Aqueous Solutions ◽  
Long Range ◽  
Transfer Functions ◽  
Aqueous Electrolyte ◽  
Tetrabutylammonium Bromide ◽  
Electrolyte Solutions ◽  
Heat Capacities ◽  
Apparent Molal Volumes ◽  
Flow Microcalorimeter ◽  
Molal Volumes

The apparent molal volumes and heat capacities of Bu4NBr were measured in aqueous solutions of NaF, NaCl, NaBr, KBr, NaAc, and NH4Ac at 25 °C with a flow densimeter and a flow microcalorimeter. The derived transfer functions of Bu4NBr from water to the electrolyte solutions, after correction for the long-range coulombic forces, are all negative. This suggests that the noncoulombic interactions between hydrophobic and hydrophilic ions result in negative contributions to volumes and heat capacities.

A Comparative Study of Bu4NBr, NaBPh4, Ph4PCl, and Ph4AsCl in Water and Methanol at 25 °C: Partial Molal Volumes, Heat Capacities, and Viscosities

1972 ◽  
Vol 50 (19) ◽  
pp. 3167-3178 ◽  
Author(s):  
C. Jolicoeur ◽  
P. R. Philip ◽  
G. Perron ◽  
P. A. Leduc ◽  
J. E. Desnoyers
Keyword(s):  
Comparative Study ◽  
Transfer Functions ◽  
Heat Capacities ◽  
Solvent Interactions ◽  
Apparent Molal Volumes ◽  
Partial Molal Volumes ◽  
Molal Volumes

The apparent molal volumes [Formula: see text] and heat capacities [Formula: see text] of Bu4NBr, NaBPh4, Ph4PCl, and Ph4AsCl have been measured in water and methanol at 25 °C in the concentration range 0.01–0.2 M. The viscosity of aqueous NaBPh4 and Ph4AsCl have also been measured at 25 °C and in the same concentration range. Individual ionic values have been estimated for most of these properties. A comparison of these values for the quaternary ions BU4N+, [Formula: see text], Ph4P+, Ph4As+ illustrates sizable differences in the solute–solvent interactions of alkyl and aryl substituted ions. Some specificity is also suggested in the solvation of the tetraphenyl ions, as shown by a comparison of the properties which should reflect directly the size of the ions [Formula: see text]and also in (H2O → CH3OH) transfer functions.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

Model for Epitaxial growth of Cobalt on CU(100)

1989 ◽  
Vol 160 ◽  
Author(s):  
Dimitri D. Vvedensky ◽  
Shaun Clarke
Keyword(s):  
Epitaxial Growth ◽  
Growth Kinetics ◽  
Solid Model ◽  
Free Energies ◽  
Diffusion Parameters ◽  
The Difference ◽  
Kinetics Of

AbstractThe epitaxial growth kinetics of Co on Cu(100) are investigated with a kinetic solid-on-solid model. Two effects are found to dominate the growth of this system reflecting the difference in surface free energies betweenthe two materials: the difference of diffusion parameters, and the inability of Co to wet Cu(100) at lower temperatures.

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