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.

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.

scholarly journals Apparent Molal Volumes and Heat Capacities of Some Tetraalkylammonium Bromides, Alkyltrimethylammonium Bromides, and Alkali Halides in Aqueous Glycerol Solutions

1975 ◽  
Vol 53 (22) ◽  
pp. 3452-3461 ◽  
Author(s):  
Giuseppa DiPaola ◽  
Bernard Belleau
Keyword(s):  
Transfer Functions ◽  
Water Structure ◽  
Alkali Halides ◽  
Heat Capacities ◽  
Glycerol Water ◽  
Tetraalkylammonium Bromides ◽  
Specific Heats ◽  
Alkyltrimethylammonium Bromides ◽  
In Series ◽  
Water Glycerol

The densities and volumetric specific heats of some tetraalkylammonium bromides, alkyltrimethylammonium bromides, and some alkali halides (0.02 to 0.5 aquamolal) were measured in 0 to 30 wt.% glycerol in water with a flow densimeter connected in series with a flow microcalorimeter at 24 and 25 °C respectively. The derived volumes and heat capacities of transfer of the electrolytes from water to glycerol–water mixtures are consistent with the corresponding transfer functions from water to D2O and from water to urea–water mixtures, and suggest that structural interactions are reduced in aqueous glycerol solutions. The volumes and heat capacities of micellisation of n-nonyltrimethylammonium bromide were determined in water, glycerol–water mixtures, urea–water mixtures, and in D2O. Both the transfer and the micellisation study indicate that glycerol behaves in an analogous manner to urea. An effect other than a simple alteration of the water structure must be invoked to account for their different effects on protein stability.

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

1976 ◽  
Vol 54 (4) ◽  
pp. 624-631 ◽  
Author(s):  
Carmel Jolicoeur ◽  
Ghyslain Lacroix
Keyword(s):  
Butyl Alcohol ◽  
Heat Capacities ◽  
Apparent Molal Volume ◽  
Molal Volume ◽  
Specific Effects ◽  
Alkyl Groups ◽  
Tert Butyl Alcohol ◽  
Dilute Aqueous Solutions ◽  
Solute Interactions ◽  
Molal Volumes

The density and specific heat of dilute aqueous solutions of various alcohols and polyols have been measured at 25 °C. Such measurements have been carried out for the following solutes: methanol, ethanol, n-propanol, n-butanol, isobutanol, s-butanol, tert-butyl alcohol, n-pentanol. 3-pentanol, neo-pentanol, ethyleneglycol, 1,4-butanediol, 1,6-hexanediol, dimethyl-2,2-propanediol, 1,1,1-tris(hydroxymethyl)ethane, and pentaerythritol.The limiting apparent molal volume [Formula: see text] and heat capacities [Formula: see text] derived from these data exhibit some variations among the properties of isomers (e.g. branched vs. normal alkyl groups), but these variations cannot be conclusively attributed to specific effects in the hydration of the alkyl groups. On the other hand, the data allows one to derive group contributions to [Formula: see text] and [Formula: see text] namely [Formula: see text] for the methylene group, [Formula: see text] for the OH functional group and [Formula: see text] for the C—H of a terminal methyl group.The concentration dependence of [Formula: see text] brings out some interesting new features. With most of the alcohols, [Formula: see text] decreases with concentration, in a way related to the degree of hydrophobicity of the alcohol. Solute–solute interactions contribute to reduce [Formula: see text] of the hydrophilic solutes, but the opposite effect is observed with the most hydrophobic alcohols.

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.

Apparent Molal Volumes and Heat Capacities of Alkaline Earth Chlorides in Water at 25 °C

1974 ◽  
Vol 52 (22) ◽  
pp. 3738-3741 ◽  
Author(s):  
Gérald Perron ◽  
Jacques E. Desnoyers ◽  
Frank J. Millero
Keyword(s):  
Alkaline Earth ◽  
Heat Capacities ◽  
Apparent Molal Volumes ◽  
Flow Microcalorimeter ◽  
Specific Heats ◽  
Molal Volumes ◽  
Alkaline Earth Chlorides

The densities and volumetric specific heats of the alkaline earth chlorides have been measured in water at 25 °C in the concentration range 0.01 to 0.4 M with a flow densimeter and a flow microcalorimeter. Apparent molal volumes and heat capacities have been derived.

Apparent Molal Volumes and Heat Capacities of some Sulfates and Carbonates in Water at 25 °C

1975 ◽  
Vol 53 (8) ◽  
pp. 1134-1138 ◽  
Author(s):  
Gérald Perron ◽  
Jacques E. Desnoyers ◽  
Frank J. Millero
Keyword(s):  
Heat Capacity ◽  
Ionic Strength ◽  
Ion Pair ◽  
Heat Capacities ◽  
Anomalous Increase ◽  
Low Concentration ◽  
Apparent Molal Volumes ◽  
Specific Heats ◽  
Molal Volumes ◽  
Apparent Molal Heat Capacities

The densities and volumetric specific heats of Na2SO4, K2SO4, MgSO4, Na2CO3, NaHCO3, and NaOH were measured up to an ionic strength of 1 in water at 25 °C with a flow densimeter and a flow microcalorimeter. From these data, the heat capacity for the formation of the ion pair MgSO40was evaluated as 84.9 J K−1 mol−1. There is an anomalous increase in the apparent molal heat capacities of Na2CO3 at low concentration but the apparent molal volumes are normal. This anomaly can be suppressed with NaOH. Attempts to account quantitatively for this behavior by an hydrolysis correction were not successful.

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.

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