Interactions between cations and sugars. II. Enthalpies, heat capacities, and volumes of aqueous solutions of Ca2+–D-ribose and Ca2+–D-arabinose at 25 °C

1986 ◽  
Vol 64 (5) ◽  
pp. 996-1001 ◽  
Author(s):  
Jean-Pierre Morel ◽  
Claude Lhermet ◽  
Nicole Morel-Desrosiers
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Solutions ◽  
Association Constant ◽  
Pair Interaction ◽  
Heat Capacities ◽  
Enthalpies Of Solution ◽  
Weak Association ◽  
Molal Volumes ◽  
Apparent Molal Heat Capacities ◽  
Entropy Of Reaction

The thermodynamic parameters characterizing the interaction between Ca2+ and the suitably positioned sequences of hydroxyls of some sugar isomers have been determined. This was done by comparing the properties of D-ribose which bears such sequences of hydroxyls with the properties of D-arabinose chosen as an inactive reference. The enthalpies of solution and of dilution, the apparent molal heat capacities, and the apparent molal volumes of the two pentoses have been first measured in water at 25 °C. The measurement of these properties for the transfer of the sugars from water to CaCl2 solutions (and, conversely, for the transfer of CaCl2 from water to the sugar solutions) directly gives access to the Ca2+–hydroxyls pair interaction parameters. The thermodynamic properties of this reaction of association may then be estimated: [Formula: see text][Formula: see text] The analysis of these data shows that the weak association constant results from a large compensation between the favourable enthalpy and the unfavourable entropy of reaction.

Apparent molal heat capacities and volumes of aqueous electrolytes at 25 °C: NaClO3, NaClO4, NaNO3, NaBrO3, NaIO3, KClO3, KBrO3, KIO3, NH4NO3, NH4Cl, and NH4ClO4

1978 ◽  
Vol 56 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Alain Roux ◽  
Goolam M. Musbally ◽  
Gérald Perron ◽  
Jacques E. Desnoyers ◽  
Prem Paul Singh ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Infinite Dilution ◽  
Heat Capacities ◽  
Aqueous Electrolytes ◽  
Apparent Molal Volumes ◽  
Hückel Theory ◽  
Standard Values ◽  
Molal Volumes ◽  
Apparent Molal Heat Capacities

Measurements at 25 °C with flow calorimeters and densimeters have led to heat capacities and densities of aqueous solutions of 11 1:1 electrolytes: NaClO3, NaBrO3, NaIO3, NaNO3, NaClO4, NH4NO3, KClO3, KBrO3, KIO3, NH4Cl, and NH4ClO4. The first 6 salts were studied up to near saturation. We have used results of these measurements to obtain apparent molal heat capacities and apparent molal volumes of the various solutes. Extrapolation to infinite dilution on the basis of the Debye–Hückel theory bas led to [Formula: see text]and [Formula: see text] values for each solute. We have compared these standard values with results of earlier investigations.

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.

Calorimetric study of the digestion of gibbsite, Al(OH)3(cr), and thermodynamics of aqueous aluminate ion, Al(OH)4−(aq)

1991 ◽  
Vol 69 (11) ◽  
pp. 1685-1690 ◽  
Author(s):  
Qiyuan Chen ◽  
Yuming Xu ◽  
Loren G. Hepler
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Sodium Hydroxide ◽  
Sodium Aluminate ◽  
Heat Capacities ◽  
Enthalpies Of Formation ◽  
Calorimetric Study ◽  
Enthalpies Of Solution ◽  
Calorimetric Measurements ◽  
Wide Range ◽  
Standard Enthalpies Of Formation

We have made calorimetric measurements of the enthalpies of solution of gibbsite, Al(OH)3(cr), in aqueous sodium hydroxide solutions at five temperatures from 100 to 150 °C. Results of these measurements have been used to obtain the standard enthalpies of formation of Na+(aq) + Al(OH)4−(aq) at the experimental temperatures. These results have also led to values of ΔCp0 for the reaction represented concisely by Al(OH)3(cr) + OH−(aq) = Al(OH)4−(aq), from which we have obtained standard state partial molar heat capacities of Na+(aq) + Al(OH)4−(aq). Combination of our results with those from earlier investigations has permitted calculation of thermodynamic properties of Na+(aq) + Al(OH)4−(aq) over a wide range of temperature and thence some generalizations about the usefulness of various equations for representing or predicting these thermodynamic properties. Key words: gibbsite, enthalpy of solution; sodium aluminate (aqueous), thermodynamic properties; heat capacities, Na+(aq) + Al(OH)4−(aq).

Heat capacities and volumes of dilute aqueous solutions of 1,3-dioxane and trioxane

1981 ◽  
Vol 59 (17) ◽  
pp. 2599-2600 ◽  
Author(s):  
Gérald Perron ◽  
Jacques E. Desnoyers
Keyword(s):  
Aqueous Solutions ◽  
Concentration Dependence ◽  
Infinite Dilution ◽  
Unit Volume ◽  
Heat Capacities ◽  
Cyclic Ethers ◽  
Group Additivity ◽  
Simple Correlation ◽  
Dilute Aqueous Solutions ◽  
Molal Volumes

The densities and heat capacities per unit volume of 1,3-dioxane and trioxane were measured in water at 25 °C in the concentration range 0.1 to 1 mol kg−1. Apparent molal volumes [Formula: see text] and [Formula: see text] heat capacities were derived. The infinite dilution [Formula: see text] shows excellent group additivity with other cyclic ethers in water but the additivity is less satisfactory for[Formula: see text]. No simple correlation can be made for the concentration dependence of these functions.

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