Excess partial molar enthalpies of water in water–tert-butanol mixtures

1988 ◽  
Vol 66 (12) ◽  
pp. 3171-3175 ◽  
Author(s):  
Yoshikata Koga
Keyword(s):  
Excess Free Energy ◽  
Liquid Structure ◽  
Pure Liquid ◽  
Thermodynamic Quantities ◽  
Hydrogen Bond Network ◽  
Rich Region ◽  
Tert Butanol ◽  
Chemical Potentials ◽  
Bond Network ◽  
Partial Molar Enthalpies

The excess partial molar enthalpies of H2O, HmE(H2O) in water–tert-butanol mixtures were measured at 30.00, 36.75, and 40.45°. Using the values of HmE(TBA) of the previous work (Y. Koga, Can. J. Chem. 66, 1187 (1988)), the excess (integral) molar enthalpies of the solution, HmE, were calculated at 30.00 °C, and compared with the literature values. The comparison was satisfactory. From the literature values of the excess free energy, the chemical potentials of each component were evaluated for the range, xTBA > 0.1. With the measured values of the excess partial molar enthalpies, the excess partial molar entropies were also calculated. These partial molar thermodynamic quantities and their dependence on temperature and composition clearly support the following views: (1) in the intermediate region, 0.1 < xTBA < 0.5, the system is very close to a critical demixing, and (2) in the TBA-rich region, xTBA > 0.6, TBA molecules in the solution are in almost the same environment as in the pure liquid, while H2O molecules lose the hydrogen bond network completely and are dispersed in the TBA liquid structure.

Excess partial molar enthalpies of tert-butanol in water–tert-butanol mixtures

1988 ◽  
Vol 66 (5) ◽  
pp. 1187-1193 ◽  
Author(s):  
Yoshikata Koga
Keyword(s):  
Hydrogen Bond ◽  
Solution Temperature ◽  
Hydrogen Bond Network ◽  
Critical Solution Temperature ◽  
Tert Butanol ◽  
Boiling Points ◽  
Enthalpic Interaction ◽  
Higher Temperature ◽  
Bond Network ◽  
Partial Molar Enthalpies

Excess partial molar enthalpies of tert-butanol (TBA) in water–tert-butanol mixtures were measured at 20.00, 26.90, 45.17, and 59.49 °C in the water-rich region, and at 30.00 °C for the entire range. The results together with those of the previous work, (Y. Koga. Can. J. Chem. 64, 206 (1986)), appear to support the following views: At XTBA ≈ 0, TBA molecules form hydrogen bonds with H2O molecules, and they enhance the structure of the hydrogen bond network of H2O. The latter effect is of very long range; the enthalpic repulsion between solutes is already operative via enhancement of hydrogen bond network when two TBA molecules are separated by 12 H2O molecules. This enthalpic repulsion becomes stronger as the concentration of TBA increases. At a certain threshold, XTBA ≈ 0.03 at 30.00 °C for example, the new scheme in which solutes tend to associate sets in, and for XTBA > 0.06 this scheme becomes predominant. The effect of higher temperature is to shift this threshold to the lower values of XTBA. Therefore, it is probable that a lower critical solution temperature may exist at a temperature higher than the boiling points of the solution. It was also shown that if species of TBA(H2O)k type persist, they exhibit a hard-sphere nature in terms of enthalpic interaction among themselves.

Ionic conductivity in the water-rich region of aqueous 2-butoxyethanol

1995 ◽  
Vol 73 (8) ◽  
pp. 1294-1297 ◽  
Author(s):  
Yoshikata Koga ◽  
Virginia J. Loo ◽  
Kataryna T. Puhacz
Keyword(s):  
Hydrogen Bond ◽  
Ionic Conductivity ◽  
Aqueous Solutions ◽  
Infinite Dilution ◽  
Ionic Conductivities ◽  
Molar Conductivity ◽  
Hydrogen Bond Network ◽  
Rich Region ◽  
Mixing Schemes ◽  
Bond Network

Ionic conductivities of HCl, KOH, and KCl were measured in aqueous solutions of 2-butoxyethanol (BE) at 25 °C. The quantity, Λj′ = σ/xj, which is almost proportional to the molar conductivity, was extrapolated to the infinite dilution xj → 0. σ is the conductivity and xj is the mole fraction of j(= HCl, KOH, or KCl). The plots of 0Λj′, the value of Λj′ extrapolated to infinite dilution, against xBE showed a change in slope at xBE = 0.0175. The previous work from this laboratory indicated that the mixing scheme changes qualitatively at the same locus, xBE = 0.0175. By mixing scheme we simply mean the way in which BE and H2O molecules mix with each other. Assuming additivity in 0Λj′ in terms of constituent ions, those values for H+OH− were calculated. Plots of [Formula: see text] thus calculated as a function of xBE in the water-rich region, 0 < xBE < 0.0175, suggest that the hydrogen bond probability decreases in the bulk of solution, as xBE increases. Keywords: aqueous 2-butoxyethanol, ionic conductivities, mixing schemes, hydrogen bond network.

Effects of Molecular Shape on Alcohol Aggregation and Water Hydrogen Bond Network Behavior in Butanol Isomer Solutions

2021 ◽  
Author(s):  
Seungeui Choi ◽  
Saravanan Parameswaran ◽  
Jun-Ho Choi
Keyword(s):  
Phase Diagram ◽  
Hydrogen Bond ◽  
Liquid Phase ◽  
Molecular Shape ◽  
Hydrogen Bond Network ◽  
Network Behavior ◽  
Chemical Formula ◽  
Tert Butanol ◽  
Bond Network ◽  
Water Hydrogen

Despite that butanol isomers such as n-butanol, sec-butanol, isobutanol and tert-butanol have the same chemical formula, their liquid-liquid phase diagram is distinct. That is, the tert-butanol is miscible in water...

X-ray Crystallographic Study of Alkylammonium Anthracene-9-carboxylates as a Model for Fibrous Structure of Binary Anthracene Salt Gels

2004 ◽  
Vol 69 (6) ◽  
pp. 1292-1300 ◽  
Author(s):  
Tahahiro Tani ◽  
Kazuki Sada ◽  
Masatsugu Ayabe ◽  
Yuya Iwashita ◽  
Takanori Kishida ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Columnar Structure ◽  
Hydrogen Bond Network ◽  
One Dimensional ◽  
X Ray ◽  
Crystallographic Study ◽  
Alkylammonium Salts ◽  
Bond Network ◽  
Fibrous Assemblies ◽  
Long Alkyl Chain

Crystal structure of hexylammonium anthracene-9-carboxylate was investigated. The salt was arranged by a one-dimensional hydrogen bond network to form a columnar structure in the crystalline state. This columnar structure should be the model of fibrous assemblies in the organogels of anthracene-9-carboxylate alkylammonium salts having a long alkyl chain.

Halides of Macrocyclic Silver(II) Complexes: Crystal Structures with Hydrogen Bond Network and Reaction Kinetics of the Decomposition

2021 ◽  
pp. 120431
Author(s):  
Akinori Honda ◽  
Shunta Kakihara ◽  
Shuhei Ichimura ◽  
Kazuaki Tomono ◽  
Mina Matsushita ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Reaction Kinetics ◽  
Crystal Structures ◽  
Hydrogen Bond Network ◽  
Bond Network ◽  
Kinetics Of

scholarly journals Hydrogen‐Bond Network Determines the Early Photoisomerization of Cph1 and AnPixJ Phytochromes

2021 ◽  
Author(s):  
Xiang-Yang Liu ◽  
Teng-Shuo Zhang ◽  
Qiu Fang ◽  
Wei-Hai Fang ◽  
Leticia González ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Network ◽  
Bond Network
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