scholarly journals Thermodynamic study of the solubility of ibuprofen in acetone and dichloromethane

2010 ◽  
Vol 46 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Diana Marcela Aragón ◽  
Jaiver Eduardo Rosas ◽  
Fleming Martínez
Keyword(s):  
Hydrogen Bonds ◽  
Gibbs Energy ◽  
Transfer Process ◽  
Thermodynamic Functions ◽  
Thermodynamic Quantities ◽  
Dipolar Interactions ◽  
Solvent Interactions ◽  
Solution Processes ◽  
Enthalpy And Entropy ◽  
Solvation Processes

Thermodynamic functions, Gibbs energy, enthalpy and entropy for the solution processes of ibuprofen (IBP) in acetone and dichloromethane (DCM) were calculated from solubility values obtained at temperatures ranging from 293.15 K to 313.15 K. The respective thermodynamic functions for mixing and solvation processes as well as the activity coefficients for the solute were calculated. IBP solubility was high and proved similar in both solvents but was greater in DCM than acetone. In addition, the thermodynamic quantities for the transfer process of this drug from cyclohexane to the organic solvents were also calculated in order to estimate the contributions of hydrogen-bonds or of other dipolar interactions. The results were discussed in terms of solute-solvent interactions.

scholarly journals SOLVENT EFFECTS ON THE THERMODYNAMICS OF SOLVATION OF BARIUUM DIPHENYLAMINESULFONATE IN ETHANOL-WATER MIXED SOLVENTS

2013 ◽  
Vol 21 (21) ◽  
pp. 31-40
Author(s):  
Esam A. GOMAA ◽  
Elsayed M. ABOU ELLEET ◽  
E. T. HELMY ◽  
Sh. M. DEFRAWY
Keyword(s):  
Gibbs Energy ◽  
Thermodynamic Functions ◽  
Mixed Solvent ◽  
Mixed Solvents ◽  
Ion Association ◽  
Solvent Mixtures ◽  
Free Energies ◽  
Solvent Interactions ◽  
Solution Processes ◽  
Solvation Processes

The aim of this study was to determine the thermodynamic functions, Gibbs energy, enthalpy, and entropy for the solution processes of barium diphenylaminesulfonate in the mixed solvent (ethanol+water) were calculated from solubility values obtained at temperatures ranging from 293.15 K to 308.15 K. The respective thermodynamic, functions for mixing and solvation processes, as well as the activity coefficients for the solute were calculated. The solubility of solutes in mixed solvents depends primarily on the solvation of the solutes or their constituent ions by the components of the solvent mixtures. In this study, the solubility of this barium diphenyla1ninesuifonate in the mixed solvent (ethanol + water by value percent of ethanol= 0, 20, 40, 60, 80, and 100% by volume), was determined at different temperature by the solvent evaporation method. The results enable us to estimate the value of thermodynamic solubility product, Kop(th), of barium diphenylaminesulfonate in the mixed solvent. In addition, Gibbs energy, enthalpy, entropy for the solution processes, and free energies of transfer of barium diphenyla1ninesulfonate units from water to the ethanol solutions were also calculated in order to estimate the contributions of solute-solvent interactions related to ion association are based on changes in the electrostatic properties of the solvent, solute, and ion salvation as itself as on the ionic strength of the medium.

scholarly journals Temperature dependence of the specific heat and thermodynamic functions AК1М2 alloy, doped strontium

2019 ◽  
Vol 21 (1) ◽  
pp. 35-42 ◽  
Author(s):  
I. N. Ganiev ◽  
S. E. Otajonov ◽  
N. F. Ibrohimov ◽  
M. Mahmudov
Keyword(s):  
Heat Capacity ◽  
Gibbs Energy ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Specific Heat Capacity ◽  
Thermodynamic Functions ◽  
Inverse Relationship ◽  
Alloying Element ◽  
Enthalpy And Entropy ◽  
Increasing Temperature

In the heat «cooling» investigated the temperature dependence of the specific heat capacity and thermodynamic functions doped strontium alloy AK1М2 in the range 298,15—900 K. Mathematical models are obtained that describe the change in these properties of alloys in the temperature range 298.15—900 K, as well as on the concentration of the doping component. It was found that with increasing temperature, specific heat capacity, enthalpy and entropy alloys increase, and the concentration up to 0.5 wt.% of the alloying element decreases. Gibbs energy values have an inverse relationship, i.e., temperature — decreases the content of alloying component — is up to 0.5 wt.% growing.

scholarly journals Solubility of Butylated Hydroxytoluene (BHT) in Aqueous and Alcohol Solutions from 293.15 to 313.15 K

2014 ◽  
Vol 28 ◽  
pp. 48-58 ◽  
Author(s):  
Shipra Baluja ◽  
Kapil Bhesaniya ◽  
Rahul Bhalodia ◽  
Sumitra Chanda
Keyword(s):  
Gibbs Energy ◽  
Thermodynamic Functions ◽  
Butylated Hydroxytoluene ◽  
Solubility Data ◽  
Different Temperatures ◽  
Enthalpy And Entropy

The solubility of Butylated hydroxyl toluene in aqueous and alcohol solutions were determined at different temperatures (293.15 to 313.15) K. Using Van’t Hoff and Gibb’s equations, some thermodynamic functions such as Gibbs energy, enthalpy and entropy of dissolution, and of mixing of Butylated hydroxyl toluene in aqueous and alcohol solutions, were evaluated from solubility data. The solubility was greater in butanol and minimum in water. The enthalpies, entropy and Gibb’s energy of dissolution were positive for all solvents.

scholarly journals Temperature dependence of the heat capacity and change in the thermodynamic functions of strontium-alloyed AK1M2 alloy

2018 ◽  
Vol 4 (3) ◽  
pp. 119-124
Author(s):  
Izatullo N. Ganiev ◽  
Suhrob E. Otajonov ◽  
Nasim F. Ibrohimov ◽  
M. Mahmudov
Keyword(s):  
Heat Capacity ◽  
Gibbs Energy ◽  
Mathematical Models ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Thermodynamic Functions ◽  
Temperature Decrease ◽  
Cooling Mode ◽  
Enthalpy And Entropy ◽  
Aluminum Base

The temperature dependence of the specific heat capacity and change in the thermodynamic functions of strontium-alloyed ultrahigh-purity aluminum base AK1M2 alloy have been studied in “cooling” mode over the 298.15–900 K range. Mathematical models describing the evolution of these properties of the alloys in the abovementioned temperature range with change in alloying addition concentration have been obtained. The heat capacity, enthalpy and entropy of the alloys increase with temperature, decrease with an increase in the alloying addition concentration to 0.5 wt.% and grow with a further increase in the alloying addition concentration. The Gibbs energy of the alloys has an inverse dependence: it decreases with an increase in temperature and grows with an increase in the alloying addition concentration to 0.5 wt.%.

scholarly journals Heat capacity and thermodynamic functions of aluminum conductive alloy E-AlMgSi (Aldrey) doped with gallium

2020 ◽  
Vol 22 (3) ◽  
pp. 219-227
Author(s):  
I. N. Ganiev ◽  
F. A. Aliev ◽  
H. O. Odinazoda ◽  
A. M. Safarov ◽  
J. H. Jayloev
Keyword(s):  
Heat Capacity ◽  
Aluminum Alloys ◽  
Gibbs Energy ◽  
Thermodynamic Functions ◽  
Cooling Mode ◽  
Initial Alloy ◽  
Production And Consumption ◽  
Electrical Industry ◽  
Scope Of Application ◽  
Enthalpy And Entropy

Aluminum — a metal whose scope of application is constantly expanding. At present, aluminum and its alloys in a number of areas successfully displace traditionally used metals and alloys. The widespread use of aluminum and its alloys is due to its properties, among which, first of all, low density, satisfactory corrosion resistance and electrical conductivity, ability to apply protective and decorative coatings should be mentioned. All this, combined with the large reserves of aluminum in the earth’s crust, makes the production and consumption of aluminum very promising. One of the promising areas for the use of aluminum is the electrical industry. Conductive aluminum alloys type E-AlMgSi (Aldrey) are representatives of this group of alloys.One of the promising areas for the use of aluminum is the electrical industry. Conducting aluminum alloys of the E-AlMgSi type (Aldrey) are representatives of this group of alloys. The paper presents the results of a study of the temperature dependence of heat capacity, heat transfer coefficient, and thermodynamic functions of an aluminum alloy E-AlMgSi (Aldrey) with gallium. Research conducted in the “cooling” mode. It is shown that the temperature capacity and thermodynamic functions of the E-AlMgSi alloy (Aldrey) with gallium increase, while the Gibbs energy decreases. Gallium additives up to 1 wt.% Reduce the heat capacity, enthalpy, and entropy of the initial alloy and increase the Gibbs energy.

Solubility of nonpolar gases in 2,6-dimethylcyclohexanone

1990 ◽  
Vol 68 (3) ◽  
pp. 435-439 ◽  
Author(s):  
Maria Asuncion Gallardo ◽  
Maria Del Carmen Lopez ◽  
Jose Santiago Urieta ◽  
Celso Gutierrez Losa
Keyword(s):  
Gibbs Energy ◽  
Thermodynamic Functions ◽  
Pair Potential ◽  
Scaled Particle Theory ◽  
Gas Solubility ◽  
Particle Theory ◽  
Lennard Jones ◽  
Enthalpy And Entropy ◽  
Potential Parameters ◽  
Solubility Of Nonpolar Gases

Solubility measurements of He, Ne, Ar, Kr, Xe, H2, D2, N2, CH4, C2H4, C2H6, CF4, SF6, and CO2 in 2,6-dimethylcyclohexanone at temperatures 273.15 to 303.15 K and at a gas partial pressure of 101.33 kPa are reported. Standard changes in Gibbs energy, enthalpy, and entropy for the dissolution process at 298.15 K are also presented. Results for both solubility and thermodynamic functions are compared with those for cyclohexanone and 2-methylcyclohexanone. The scaled particle theory is used to obtain the effective Lennard–Jones (6,12) pair potential parameters for 2,6-dimethylcyclohexanone and, from these, the values it predicts for the solubility of the studied gases in the solvent are obtained. Keywords: gas solubility, Henry coefficient, 2,6-dimethylcyclohexanone, thermodynamic functions of solution, non-polar gases.

A Comparative Study of Adsorption of Aliphatic Amines at a Gold Electrode

2005 ◽  
Vol 70 (12) ◽  
pp. 2027-2037 ◽  
Author(s):  
Teresa Łuczak
Keyword(s):  
Gibbs Energy ◽  
Comparative Study ◽  
Gold Electrode ◽  
Surface Coverage ◽  
Standard Gibbs Energy ◽  
Gold Surface ◽  
Experimental Dependence ◽  
Aliphatic Amines ◽  
Solvent Interactions ◽  
Amine Concentration

Adsorption of aliphatic amines (C1-C4) at the gold electrode was studied by tensammetry. It has been established that the experimental dependence between the gold surface coverage (Θ) and the bulk amine concentration (cA) fits satisfactorily both by the Frumkin and Flory-Huggins isotherms. The standard Gibbs energy of adsorption, ∆G°ad at Emax for Θ < 0.8 has been found to increase in the order methylamine < ethylamine < propylamine < butylamine. This is rationalised in terms of surface-adsorbate, adsorbate-adsorbate and adsorbate-solvent interactions.

The Order of Phase Transition of Solvable DNA Melting Models

2003 ◽  
Vol 17 (16) ◽  
pp. 885-896 ◽  
Author(s):  
Su-Long Nyeo ◽  
I-Ching Yang
Keyword(s):  
Phase Transition ◽  
Hydrogen Bonds ◽  
Short Range ◽  
Scaling Laws ◽  
Dna Melting ◽  
Thermodynamic Quantities ◽  
Base Pairs ◽  
Order Of Phase Transition ◽  
Exactly Solvable ◽  
Dna Models

The phase transition of DNA molecules is studied in an exactly solvable formalism with the Morse and Deng–Fan potentials for the interstrand hydrogen bonds of nucleotide base pairs. It is shown that although the two potentials have different short-range behaviors, the thermodynamic quantities of the DNA system in these potentials enjoy the same scaling laws with the associated critical exponents, which are explicitly calculated. These exactly solvable DNA models are shown to exhibit a phase transition of the second order and the results of the analysis agree with previous studies.

scholarly journals Thermodynamic Study of the Solubility of Naproxen in Some 2-Propanol + Water Mixtures

2016 ◽  
Vol 12 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Diego Iván Caviedes Rubio ◽  
Gerson Andrés Rodríguez Rodríguez ◽  
Daniel Ricardo Delgado
Keyword(s):  
Gibbs Energy ◽  
Volume Fraction ◽  
Pure Water ◽  
Water Structure ◽  
Negative Slope ◽  
Driving Mechanism ◽  
Linear Plot ◽  
Enthalpy And Entropy ◽  
The Mean ◽  
Rich Mixtures

The equilibrium solubilities of the anti-inflammatory drug naproxen (NPX) in 2-propanol + water mixtures were determined at several temperatures from 298.15 to 313.15 K. The Gibbs energy, enthalpy, and entropy of solution and of mixing were obtained from these solubility data. The solubility was maximal in φ1 = 0.90 and very low in pure water at all the temperatures studied. A non-linear plot of ∆solnH° vs. ∆solnG° with negative slope from pure water up to 0.20 in volume fraction of 2-propanol and positive beyond this composition up pure 2-propanol was obtained at the mean temperature, 305.55 K. Accordingly, the driving mechanism for NPX solubility in the water-rich mixtures was the entropy, probably due to water-structure loss around non-polar moieties of the drug and for the 2-propanol-rich mixtures it was the enthalpy, probably due to its better solvation of the drug.

Sign in / Sign up

Export Citation Format

Share Document