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 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 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 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.

Experimental and Theoretical (ab initio and DFT) Analysis of UV-Vis Spectra, Thermodynamic Functions and Non-linear Optical Properties of 2-Chloro-3,4-Dimethoxybenzaldehyde

2015 ◽  
Vol 8 (2) ◽  
pp. 2122-2134
Author(s):  
Sarvendra Kumar ◽  
Rajesh Kumar ◽  
Jayant Teotia ◽  
M. K. Yadav
Keyword(s):  
Thermodynamic Functions ◽  
Title Compound ◽  
Density Functional ◽  
Structural Characteristics ◽  
Basis Sets ◽  
Ultraviolet Absorption Spectrum ◽  
Non Linear ◽  
Different Temperatures ◽  
Linear Optical Properties ◽  
Linear Optical

In the present work, UV- Visible spectra of 2-Chloro-3,4-Dimethoxybenzaldehyde (2,3,4-CDMB) compound  have been carried out experimentally and theoretically. The ultraviolet absorption spectrum of title compound in three solvents (Acetone, Diethyl Ether, CCl4) of different polarity were examined in the range of 200–500 nm. The structure of the molecule was optimized and the structural characteristics were determined by HF and DFT (B3LYP) methods with 6-31+G(d,p) and 6-311++G(d,p) as basis sets. The excitation energy, wavelength corresponds to absorption maxima () and oscillator strength (f) are calculated by Time-Dependent Density Functional Theory (TD-DFT) using B3LYP/6-31+G(d,p) and B3LYP/6-311++G(d,p) as basis sets. The electric dipole moment (μ), polarizability (α) and the first hyperpolarizability (β ) have been computed to evaluate the non-linear optical (NLO) response of the investigated compound by HF and DFT (B3LYP) with already mentioned basis sets. Thermodynamic functions of the title compound at different temperatures were also calculated.

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.

Evaluation of Thermodynamic Properties of Cerium in Liquid Cadmium Cathode Within LiCl-KCl Salt System

2016 ◽  
Author(s):  
Dalsung Yoon ◽  
Supathorn Phongikaroon
Keyword(s):  
Thermodynamic Properties ◽  
Gibbs Energy ◽  
Intermetallic Compounds ◽  
Linear Trend ◽  
Open Circuit ◽  
Salt System ◽  
Free Energies ◽  
Enthalpy And Entropy ◽  
Molten Salt System

Thermodynamic properties of Ce-Cd intermetallic compound were investigated in LiCl-KCl-CeCl3-CdCl2 molten salt system at various temperatures. Six Ce-Cd intermetallic compounds, CeCd, CeCd2, CeCd3, Ce13Cd58, CeCd6, and CeCd11 could be observed via cyclic voltammetry (CV) and the relative Gibbs free energies for the intermetallic formations were estimated by the analysis of the anodic peaks in the CV experiments. Furthermore, an open circuit chronopotentiometry which is known as a suitable method for measuring thermodynamic values of intermetallic compounds were performed. The linear trends of the relative Gibbs free energies were found by using potential difference from CV and CP methods. It can be noted that CV method can be easy and fast tool to estimate relative Gibbs energy for intermetallic compounds of Cd-Ms (metals). For the determination of standard Gibbs free energy, enthalpy, and entropy for the intermetallic formation, CP results were used. The linear trend of the Gibbs energy were obtained against temperature changing from 698 K to 823 K. From the linear relationship, the enthalpy and entropy of the formation were calculated.

Solubility of non-polar gases in cyclohexanone between 273.15 and 303.15 K at 101.32 kPa partial pressure of gas

1987 ◽  
Vol 65 (9) ◽  
pp. 2198-2202 ◽  
Author(s):  
María Asunción Gallardo ◽  
José María Melendo ◽  
José Santiago Urieta ◽  
Celso Gutierrez Losa
Keyword(s):  
Gibbs Energy ◽  
Partial Pressure ◽  
Temperature Dependence ◽  
Hard Sphere ◽  
Scaled Particle Theory ◽  
Sphere Diameter ◽  
Particle Theory ◽  
Enthalpy And Entropy

Solubility measurements of several non-polar gases (He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, C2H4, C2H6, CF4, SF6, andCO2) in cyclohexanone at 273.15 to 303.15 K and a partial pressure of gas of 101.32 kPa, are reported. Gibbs energy, enthalpy, and entropy of solution at 298.15 K and 101.32 kPa partial pressure of gas were evaluated. Effective hard-sphere diameter temperature dependence has been studied and its effect on the calculated SPT (Scaled Particle Theory) solubilities, and enthalpies and entropies of solution was also examined.

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