Enthalpic interactions in aqueous strong electrolytes upon addition of ionic liquids

The present study deals with the inter-ionic interactions between strong electrolytes and ionic liquids based on the thermodynamic properties such as excess partial molar enthalpy, HEIL, relative apparent molar enthalpy, ϕL, and the enthalpic interaction parameters.

Calorimetric Study of the Hydrogen Interaction with Ce6Ni1.67Si3

In the present work at the first time the hydrogen interaction with Ce6Ni1.67Si3 at pressure up to 45 atm and temperature 51˚C has been investigated by means of the calorimetric method. The ΔHabs. – C dependence (ΔHabs. –the partial molar enthalpy of the reaction of the hydrogen interaction with IMC, C – hydrogen concentration, C=H/IMC) was obtained.

Dilute Solution of H in bcc Ti35Cr65-xVx Alloys

The solubility of H in the solid solution phase of the Ti35Cr47V18 alloy has been investigated at high and low temperature. The Sieverts law has been found to hold for 808 K≤T≤1204 K and fail for 302 K≤T≤335 K. For H contents nH ≤0.07 (nH=H/Me) the partial molar enthalpy and partial non-configurational entropy at high temperature are:On heating the material under H2 gas pressures lower than 0.1 MPa H absorption only occurs above 700 K. Below this temperature, surface oxide films prevent H uptake. Thermal decomposition spectroscopy of the α phase carried out for nH≤0.24 exhibits a single peak whose temperature increases with decreasing nH owing to selective occupancy by H of energetically non-degenerate interstitial sites.

Thermodynamic properties of water in the water-poor region of binary water + alcohol mixtures

In our previous thermodynamic studies, we suggested that alcohol molecules in water-poor water + alcohol mixtures exist as alcohol clusters in a form similar to the pure alcohols. Here, we use calorimetry and densitometry to investigate how H2O interacts with alcohol clusters in water-poor binary aqueous mixtures of 12 different alcohols. The composition dependence of the measured excess partial molar enthalpy and volume of water (HEW and VEW), along with entropy data calculated from HEW and literature data for excess chemical potentials, showed that in water-poor solutions of small alcohols such as methanol, ethanol, and 1-propanol, mutual water–water interactions are endothermic, but entropically favorable. Conversely, in long-chain solvents such as 1-octanol and 1-decanol, the interaction is exothermic and entropically unfavorable. We suggest that these observations reflect water–alcohol hydrogen bonding in short-chain solvents and water clustering with more hydrogen bonding than in pure water or "dewetting" in mixtures of the longer alcohols, respectively. The composition dependence of HEW was also used to locate anomalies that specify the boundary between the mixing schemes characterizing the intermediate and the water-poor regions of alcohol + water mixtures.Key words: aqueous alkane-mono-ols, excess partial molar enthalpy, entropy and volume, mixing schemes.