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.

Heat capacities of aqueous electrolytes: eight 1:1 electrolytes and ΔCp0 for ionization of water at 298 K

1976 ◽  
Vol 54 (21) ◽  
pp. 3315-3318 ◽  
Author(s):  
Prem Paul Singh ◽  
Earl M. Woolley ◽  
Keith G. McCurdy ◽  
Loren G. Hepler
Keyword(s):  
Aqueous Solutions ◽  
Infinite Dilution ◽  
Heat Capacities ◽  
Aqueous Electrolytes ◽  
Flow Calorimeter ◽  
Apparent Molal Heat Capacities ◽  
Ionization Of Water

We have made measurements with a flow calorimeter leading to apparent molal heat capacities of aqueous solutions of NaCl, HCl, KBr, KCl, KOH, NaBr, HBr, and NaOH at 298 K. Results have been used to derive apparent molal heat capacities of these electrolytes at infinite dilution and thence ΔCp0 = −215.2 ± 4 J K−1mol−1 for ionization of H2O(liq) at 298 K.

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.

Apparent Molal Heat Capacities and Volumes of Tetrabutylammonium Carboxylates and Related Solutes in Water at 25 °C

1973 ◽  
Vol 51 (17) ◽  
pp. 2993-2998 ◽  
Author(s):  
Paul-André Leduc ◽  
Jacques E. Desnoyers
Keyword(s):  
Concentration Dependence ◽  
Sodium Acetate ◽  
Ammonium Acetate ◽  
Tetrabutylammonium Bromide ◽  
Heat Capacities ◽  
Ammonium Bromide ◽  
Sodium Octanoate ◽  
Apparent Molal Volumes ◽  
Molal Volumes ◽  
Apparent Molal Heat Capacities

The apparent molal volumes and heat capacities were measured in water at 25 °C with a flow digital densimeter and a flow microcalorimeter for the following salts: tetrabutylammonium octanoate, tetrabutylammonium butanoate, tetrabutylammonium bromide, ammonium acetate, ammonium chloride, ammonium bromide, sodium octanoate, and sodium acetate. The tetrabutylammonium octanoate and butanoate and sodium octanoate form micelles at 0.13, 0.6, and 0.35 M, respectively. The concentration dependence of the apparent molal volumes of the carboxylate salts is similar to that of typical hydrophobic or hydrophilic electrolytes. On the other hand, in the submicellar region, the concentration dependence of their apparent molal heat capacities is abnormal when compared with model electrolytes. It seems that the heat capacities may be reflecting interactions involving a hydrogen bonding of the carboxylate group with water.

Polyol–Water interactions. Apparent molal heat capacities and volumes of aqueous polyol solutions

1977 ◽  
Vol 55 (22) ◽  
pp. 3825-3830 ◽  
Author(s):  
Giuseppa DiPaola ◽  
Bernard Belleau
Keyword(s):  
Aqueous Solutions ◽  
Infinite Dilution ◽  
Pure Water ◽  
Water Environment ◽  
Heat Capacities ◽  
Flow Microcalorimeter ◽  
Specific Heats ◽  
Structural Interactions ◽  
Apparent Molal Heat Capacities

Volumetric specific heats (25 °C) and densities (24 °C) were measured with a flow microcalorimeter and flow densimeter for 12 polyols in water (0.05 to 2 m), and for NaCl and n-Bu4NBr in 1 m aqueous alditol solutions. The infinite dilution properties [Formula: see text] of the polyols show specificities in polyol−water interactions which are discussed in terms of the compatibility of the polyol stereochemistry and the existing water environment. The derived heat; capacities and volumes of transfer of hydrophobic and hydrophilic probes to aqueous solutions of homologous polyols suggest that structural interactions are reduced in these systems as compared to pure water.

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 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 molar heat capacities and volumes of aqueous electrolytes at 25 °C: Cr(NO3)3, LaCl3, K3Fe(CN)6, and K4Fe(CN)6

1979 ◽  
Vol 57 (21) ◽  
pp. 2798-2803 ◽  
Author(s):  
Jan J. Spitzer ◽  
Inger V. Olofsson ◽  
Prem Paul Singh ◽  
Loren G. Hepler
Keyword(s):  
Aqueous Solutions ◽  
Infinite Dilution ◽  
Heat Capacities ◽  
Aqueous Electrolytes ◽  
Standard State ◽  
Apparent Molar Heat Capacities ◽  
Molar Volumes ◽  
High Charge ◽  
Flow Calorimeter ◽  
Partial Molar Properties

We have used a flow calorimeter and a flow densimeter for measurements at 25 °C of heat capacities and densities of aqueous solutions of four electrolytes of high charge type: LaCl3, Cr(NO3)3, K3Fe(CN)6, and K4Fe(CN)6. Results of these measurements have been used for calculating corresponding apparent molar heat capacities and apparent molar volumes, which have been extrapolated to infinite dilution to obtain the corresponding standard state apparent molar and partial molar properties. Uncertainties resulting from extrapolations of heat capacities are discussed. Results of our measurements are compared with those of earlier related investigations.

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