Excess Partial Molar Enthalpies of 3-Ethoxypropan-1-amine and 3-Butoxypropan-1-amine in Water at 298.15 K

2018 ◽  
Vol 63 (2) ◽  
pp. 446-450 ◽  
Author(s):  
Maria Luísa C. J. Moita ◽  
Ângela F. S. Santos ◽  
Luís C. S. Nobre ◽  
Isabel M. S. Lampreia
Keyword(s):  
Partial Molar Enthalpies

Isotope effects on the excess partial molar enthalpies of {xCH3(CH2)3O(CH2)2O(H or D) + (1 − x)(H2O or D2O)}

1992 ◽  
Vol 24 (2) ◽  
pp. 159-165 ◽  
Author(s):  
William W.Y. Siu ◽  
Terrance Y.H. Wong ◽  
John T.W. Lai ◽  
Adam Chong ◽  
Yoshikata Koga
Keyword(s):  
Isotope Effects ◽  
Partial Molar Enthalpies

Properties of n-alcohol + n-alkane mixtures

1977 ◽  
Vol 30 (1) ◽  
pp. 43 ◽  
Author(s):  
F Smith
Keyword(s):  
P Systems ◽  
Effect Of Temperature ◽  
P System ◽  
Range Data ◽  
Free Energies ◽  
Dipole Term ◽  
Partial Molar Enthalpies ◽  
Refined Estimate ◽  
Two Parameters ◽  
Latent Heats

The total polar contributions (AP) to three properties [infrared absorbance, mixing enthalpies (HM) and excess free energies (GE)] of alcohol + alkane (alp) systems are separated into a direct hydrogenbond contribution ( AB) from the formation of isolated imers and a dipole-dipole contribution (AD) resulting from dipolar correlation between these transient imers. Dilute concentration range data giving the AB contributions to these properties were found dependent only on OH group concentration (c) and are used to show the serious inadequacies of previous theories. A new proposed association model having only two parameters, that are fixed for all systems, does give good results for the AB contributions and further is quite compatible with the effect of temperature change and with the n.m.r. chemical shift (ε) and apparent mean square dipole moment (p2) data that are also studied. Thus association theory has been made quantitative for the AB contributions to three properties of a/p systems and the approach given for deriving models appears capable of wider application. The model was used to extrapolate the AB contributions into the concentrated alcohol range to thus give the AD contributions by difference. The latter are then shown to be the origin of the distinctive behaviour shown by lower alcohols in their pure and binary mixture properties either with alkanes or with other alcohols where for the latter the principle of congruence is shown to be completely misleading. Two contributions (Ag and AD) explain the different c dependence shown by the i.r., HM and the δ data for a/p systems and, qualitatively, the HM data for alcohol+alcohol systems while the existence of a significant dipole term is strongly supported by the remarkable similarities found between the p2(c) data and the derived dipole-dipole contribution to the entropy of a/p systems. A method is given for predicting latent heats and partial molar enthalpies of higher alcohols from the HM data for one a/p system and a refined estimate is made of the enthalpy of formation of a hydrogen bond. Polar structure and non-linear dielectric effects are also discussed.

scholarly journals Measurements of Activity Coefficients at Infinite Dilution for Organic Solutes in the Ionic Liquids N-Ethyl- and N-Octyl-N-methylmorpholinium Bis(trifluoromethanesulfonyl)imide. A Useful Tool for Solvent Selection

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 634 ◽  
Author(s):  
Łukasz Marcinkowski ◽  
Joachim Eichenlaub ◽  
Elham Ghasemi ◽  
Żaneta Polkowska ◽  
Adam Kloskowski
Keyword(s):  
Ionic Liquids ◽  
Organic Compounds ◽  
Activity Coefficients ◽  
Infinite Dilution ◽  
Retention Data ◽  
Separation Processes ◽  
Study Results ◽  
Conscious Choice ◽  
Potential Applications ◽  
Partial Molar Enthalpies

In recent years, many papers describing ionic liquids (IL) as promising solvents in separation techniques have been published. The conscious choice of appropriate ionic liquid as absorption media in effective extraction of selected types of analytes requires deeper understanding of the analyte−IL interactions. Therefore, intensive research is conducted to determine the values of activity coefficient at infinite dilution, which allows us to characterize the nature of these interactions. Based on the inverse gas chromatography retention data, activity coefficients at infinite dilution γ 13 ∞ of 48 different organic compounds in the ionic liquids N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide [C2C1Mor][TFSI] and N-octyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide [C8C1Mor][TFSI] were determined. The measurements covered a broad range of volatile organic compounds, including n-alkanes, n-alkenes, n-alkynes, alcohols, aldehydes, ketones, aromatic compounds and common polar solvents, representing different types of interactions. Activity coefficients at infinite dilution were measured in the temperature range from 313.15 to 363.15 K. The excess partial molar enthalpies and entropies at infinite dilution were determined. Selectivity at infinite dilution was also calculated for exemplary separation processes in the hexane/benzene system. The obtained results were analyzed and compared with literature data for ionic liquids containing the same anion [TFSI]¯ and different cations. The study results indicate that some potential applications of the investigated ionic liquids in separation problems exist.

Thermodynamic properties of peptide solutions. The relative partial molar enthalpies of aqueous solutions of glycylglycylglycine, glycylglycylalanine and alanylglycylglycine

1983 ◽  
Vol 36 (9) ◽  
pp. 1813 ◽  
Author(s):  
MK Kumaran ◽  
ID Watson ◽  
GR Hedwig
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Solutions ◽  
Side Chain ◽  
Enthalpies Of Dilution ◽  
Flow Microcalorimetry ◽  
Water Side ◽  
Partial Molar Enthalpies

The enthalpies of dilution at 298 K of aqueous solutions of the tripeptides glycylglycylglycine, glycylglycylalanine and alanylglycylglycine have been determined by flow microcalorimetry. From these data the partial molar enthalpies of the solvent in the solutions have been calculated. The results indicate that water side-chain interactions make an important contribution to the solvation of peptides.

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