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.

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.

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.

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.

Apparent molar heat capacities and volumes of aqueous electrolytes at 25 °C: Na2SO4, K2SO4, Na2S2O3, Na2S2O8, K2S2O8, K2CrO4, Na2MoO4, and Na2WO4

1978 ◽  
Vol 56 (14) ◽  
pp. 1871-1873 ◽  
Author(s):  
Inger V. Olofsson ◽  
Jan J. Spitzer ◽  
Loren G. Hepler
Keyword(s):  
Aqueous Solutions ◽  
Infinite Dilution ◽  
Heat Capacities ◽  
Aqueous Electrolytes ◽  
Standard State ◽  
Apparent Molar Heat Capacities ◽  
Density Measurements ◽  
Dilute Aqueous Solutions

We have made beat capacity and density measurements leading to apparent molar beat capacities and volumes for dilute aqueous solutions of Na2SO4, K2SO4, Na2S2O3, Na2S2O8, K2S2O8, K2CrO4, Na2MoO4, and Na2WO4. We have used these apparent molar quantifies to extrapolate to infinite dilution to obtain the corresponding standard state apparent and partial molar quantities. These latter values have been used in calculation of conventional ionic beat capacities and volumes.

Aqueous solutions of azoniaspiroalkane halides. VI. Apparent molal volumes and apparent molal heat capacities of chlorides and iodides

1979 ◽  
Vol 8 (6) ◽  
pp. 449-460 ◽  
Author(s):  
Antonio Lo Surdo ◽  
Wen-Yang Wen ◽  
Carmel Jolicoeur
Keyword(s):  
Aqueous Solutions ◽  
Heat Capacities ◽  
Apparent Molal Volumes ◽  
Molal Volumes ◽  
Apparent Molal Heat Capacities

Apparent molar heat capacities and volumes of unsaturated heterocyclic solutes in aqueous solution at 25 °C

1980 ◽  
Vol 58 (7) ◽  
pp. 704-707 ◽  
Author(s):  
Octavian Enea ◽  
Carmel Jolicoeur ◽  
Loren G. Hepler
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Heterocyclic Compounds ◽  
Infinite Dilution ◽  
Heat Capacities ◽  
Group Additivity ◽  
Standard State ◽  
Apparent Molar Heat Capacities ◽  
Partial Molar Heat Capacities

Measurements at 25 °C with flow calorimeters and densimeters have led to heat capacities and densities of aqueous solutions of 15 unsaturated heterocyclic compounds containing nitrogen. From the results of these measurements we have obtained apparent molar heat capacities and volumes of the solutes. Extrapolations to infinite dilution have led to corresponding standard state apparent and partial molar heat capacities and volumes, which have been analyzed in terms of atomic and group additivity relationships.

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 amino acids in aqueous polyol solutions

1978 ◽  
Vol 56 (13) ◽  
pp. 1827-1831 ◽  
Author(s):  
Giuseppa DiPaola ◽  
Bernard Belleau
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aqueous Solutions ◽  
Transfer Functions ◽  
Heat Capacities ◽  
Side Chains ◽  
Dilute Solutions ◽  
Flow Microcalorimeter ◽  
Regular Increase ◽  
Apparent Molal Heat Capacities

Densities (24 °C) and volumetric specific beats (25 °C) were measured for amino acids (0.05–0.5 m) containing apolar side chains in water, and in aqueous solutions of glycerol, mannitol, sorbitol, NaCl, urea, and Gu•HCl, with a flow densimeter and flow microcalorimeter respectively.The derived apparent molal quantifies and transfer functions of the amino acids in aqueous polyol solutions reveal no specificities which might explain the origin of the unique behavior of polyols in protein systems. However, the study did reveal a regular increase in the structure-making ability of the amino acid as the hydrophobicity of the side chains increased. This structure-making tendency was reduced significantly in dilute solutions of the higher polyols.

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