The extraction of Co2+ from aqueous 0.1M acetate buffer by thenoyltrifluoroacetone (HTTA) and 8-hydroxyquinoline (HQ) and by a mixture of HTTA+phen and HQ+phen in benzene has been studied at various temperatures allowing for elucidation of the thermodynamics of extraction in the cases investigated.
Authors:Qi Yang, Gang Xie, Sanping Chen, and Shengli Gao
is determined. The thermodynamics of the reaction of formation in water at different temperatures are investigated, and fundamental parameters are obtained on the basis of reaction thermodynamic and thermokinetic equations
The aim of this investigation was to study the influence of electrolytes on a reaction of triiodide complex formation. Investigation
of the salt effect as concerns the thermodynamics of I
formation in methanol, ethanol and n-propanol solutions revealed regularities of the influence of the electrolyte on triiodide
complex formation connected with a multifactorial effect of the ionic medium. The quasichemical model presented was used to
calculate parameters reflecting the overall salt effect.
Contributions of modern, temperature-modulated calorimetry
are qualitatively and quantitatively discussed. The limitations are summarized,
and it is shown that their understanding leads to new advances in instrumentation
and measurement. The new thermal analysis experiments allow to separate reversing
from irreversible processes. This opens the irreversible states and transitions
to a description in terms of equilibrium and irreversible thermodynamics.
Amorphous systems can be treated frommacroscopic to nanometer sizes with weak
to strong coupling between neighboring phases. Semicrystalline, macromolecular
systems are understood on the basis of modulated calorimetry as globally metastable,
micro-to-nanophase-separated systems with locally reversible transitions.
Authors:Nacer Ferrah, Omar Abderrahim, Mohamed Didi, and Didier Villemin
A novel sorbent resin consisting of a Phosphonic Acid grafted on Merrifield Resin (PA-MR) for the extraction of uranyl from
nitrate media is described. The sorption behaviour of uranyl cation on PA-MR was investigated using batch equilibrium technique.
The effects of parameters such as shaking speed, pH levels, contact time, metal concentrations, ionic strength and temperature
were reported. The results show that the sorption capacity increases with increasing both initial uranyl ion concentration
and temperature and decreases with increasing ionic strength. Therefore, the optimum condition for the present study should
be using 6.6 mg adsorbent per 1.0 mg uranyl in solution with pH 3.6 and shaking at 250 rpm for 180 min. The adsorption behavior
of the system was also investigated and found to be in line with Langmuir isotherm. The kinetic data was well described by
the pseudo second-order. Thermodynamics data leads to endothermic process ∆H = + 31.03 kJ−1 mol−1, ∆S = + 146.64 J mol−1 K−1 and ∆G = −11.96 kJ mol−1 at 20 K. ∆G decreased to negatives values with increasing temperature indicating that the process was more favoured at high temperature.
Authors:S. Mishra, S. Maity, S. Bhalke, G. Pandit, V. Puranik, and H. Kushwaha
In order to understand the mobility of uranium it is very important to know about its sorption kinetics and the thermodynamics
behind the sorption process on soil. In the present study the sorption kinetics of uranium was studied in soil and the influence
parameters to the sorption process, such as initial uranium concentration, pH, contact time and temperature were investigated.
Distribution coefficient of uranium on soil was measured by laboratory batch method. Experimental isotherms evaluated from
the distribution coefficients were fit to Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models. The sorption energy
for uranium from the D–R adsorption isotherm was calculated to be 7.07 kJ mol−1.The values of ΔH and ΔS were calculated to be 37.33 kJ mol−1 and 162 J K−1 mol−1, respectively. ΔG at 30 °C was estimated to be −11.76 kJ mol−1. From sorption kinetics of uranium the reaction rate was calculated to be 1.6 × 10−3 min−1.
As represented by equations in which there is a term representing the biomass, the thermodynamics of biological growth processes
is difficult to study without knowing the thermodynamic properties of cellular structural fabric. Measurement of the heat
capacity data required to determine the standard entropy, S
298,15 or the standard absorbed heat, (H298,15-ΔH0=Θ298,15 of biomass requires a low-temperature calorimter, and these are not present in most laboratories. Based on a previously described
method for entropy, two equations are developed that enable values of the absorbed heat (Θ298,15) and the absorbed heat of formation, (ΔfΘ298,15) for biomass to be calculated empirically which are accurate to within 1% with respect to the biomass substances tested.
These equations depend on a previous knowledge of the atomic composition or the unit-carbon formulas of macromolecules or
structural cellular fabric.
Authors:Dmitry Yu. Murzin, Olga A. Simakova, Irina L. Simakova, and Valentin N. Parmon
different pH (data taken from [ 4 ])
Even if the model is able to explain experimental observations, it should be explicitly pointed out here that the real thermodynamics could be more complicated than the one considered
Authors:Xuehang Wu, Wenwei Wu, Xuemin Cui, and Sen Liao
2 O with controlled morphologies via solid-state reaction at low heat [ 20 , 21 ] and to study the kinetics and thermodynamics of the decomposition of MnV 2 O 6 ·4H 2 O using DSC technique. Non-isothermal kinetics of the decomposition process of MnV
enthalpies of solution are known and the thermodynamics of the solutions have rarely been reported.
In this article, the thermochemical properties including Δ sol H m , Δ sol G m , Δ sol S m , Δ sol S m (app), Δ sol S m (partial) of resveratrol