Thermodynamical detection of hydrophobic hydration of tris(2,4-pentanedionato)-cobalt(III) and tris(3,5-heptanedionato)cobalt(III) in water

1991 ◽  
Vol 69 (9) ◽  
pp. 1388-1393 ◽  
Author(s):  
Yasuki Yoshimura
Keyword(s):  
Free Energy ◽  
Aqueous Solutions ◽  
Temperature Dependence ◽  
Key Words ◽  
Thermodynamic Parameters ◽  
Hydrophobic Hydration ◽  
Thermodynamic Quantities ◽  
Temperature Range ◽  
Entropy Formula ◽  
Energy Formula

The solubilities of tris(2,4-pentanedionato)cobalt(III) and tris(3,5-heptanedionato)cobalt(III) in water, heptane, and 1,2-ethanediol were determined over the temperature range 5–50 °C and from these data the thermodynamic quantities of solution at 25 °C were estimated. The free energy [Formula: see text], enthalpy [Formula: see text], and entropy [Formula: see text] of transfer of these chelates from heptane to some solvents were calculated from the corresponding thermodynamic quantities of solution. When [Formula: see text] and [Formula: see text] were separately plotted against [Formula: see text], the data of transfer from heptane to water deviated markedly from a correlation obtained for the data of transfer to the solvents other than water. This finding indicates that these chelates are subject to hydrophobic hydration in their aqueous solutions. The solubility of tris(glycinato)cobalt(III) in water was also determined over the temperature range 5–60 °C and its temperature dependence of the solubility is compared with that for the cobalt(III) chelates of the β-diketones. Key words: tris cobalt(III) chelates of β-diketones and glycine, temperature dependence of solubility, thermodynamic parameters of solution, thermodynamic parameters of transfer, hydrophobic hydration.

scholarly journals Study on Adsorption of Cu and Ba from Aqueous Solutions Using Nanoparticles of Origanum (OR) and Lavandula (LV)

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ghadah M. Al-Senani ◽  
Foziah F. Al-Fawzan
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Free Energy ◽  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Solution Ph ◽  
Environment Friendly ◽  
Removal Of Heavy Metals ◽  
Equilibrium Data ◽  
Langmuir And Freundlich Models

Wild herbs (Origanum (OR) and Lavandula (LV)) were used as environment-friendly adsorbents in this study. The adsorbents were used for adsorption of Cu and Ba from water. The adsorption of heavy metals onto OR and LV was dependent on particle size, dose, and solution pH. The diameter of adsorbent particles was less than 282.8 nm. The adsorption follows second-order kinetics. Langmuir and Freundlich models have been applied to describe the equilibrium data, and the thermodynamic parameters, the Gibbs free energy, ∆G°, enthalpy, ∆H°, and entropy, ∆S°, have been determined. The positive value of ∆H° suggests that the adsorption of heavy metals by the wild herbs is endothermic. The negative values of ∆G° at all the studied temperatures indicate that the adsorption is a spontaneous process. It can be concluded that OR and LV are promising adsorbents for the removal of heavy metals from aqueous solutions over a range of concentrations.

Modeling batch kinetics of cesium, cobalt and strontium ions adsorption from aqueous solutions using hydrous titanium oxide

2007 ◽  
Vol 95 (7) ◽  
Author(s):  
E. Metwally ◽  
R. O. Abdel Rahman ◽  
R. R. Ayoub
Keyword(s):  
Free Energy ◽  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Titanium Oxide ◽  
Contact Time ◽  
Cobalt Ions ◽  
Batch Kinetics ◽  
Batch Technique ◽  
Strontium Ions ◽  
Kinetics Of

Hydrous titanium oxide was chemically synthesized and tested as adsorbent material for the removal of cesium, cobalt and strontium ions from chloride waste solutions using batch technique. The influences of pH, contact time, and temperature have been reported. The uptake of both strontium and cobalt ions was found to be greater than that of cesium and the apparent sorption capacity of each ion increases with increase in temperature. Thermodynamic parameters such as changes in Gibbs free energy (Δ

The thermodynamics of the vaporization of liquid indium(I) bromide by modified entrainment

1991 ◽  
Vol 69 (9) ◽  
pp. 1394-1397 ◽  
Author(s):  
Peter J. Gardner ◽  
Steve R. Preston
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Key Words ◽  
Vapour Pressure ◽  
Carrier Gas ◽  
Temperature Range ◽  
Liquid Indium

The transport of gaseous In(I)Br in an argon carrier gas was studied in the temperature range 680 to 935 K by the modified entrainment method. Combination of the entrainment results with a literature equation for the total vapour pressure above the liquid gave the following expressions for the temperature dependence of the vapour pressures of the monomer (In2Br2) and dimer (In2Br2) respectively: [Formula: see text] ln T − 0.001164 ± 0.00021)T, (680 −950 K) and [Formula: see text] (680–810 K); p0 = 105 Pa. The dimer concentration is ca. 14% at 680 K and decreases to ca. 4% at 810 K. Key words: high temperature thermodynamics, indium(I) bromide, vaporization thermodynamics.

Oil and water do not mix—hydrophobic hydration

Surfactants ◽  
2019 ◽  
pp. 17-24
Author(s):  
Bob Aveyard
Keyword(s):  
Free Energy ◽  
Water Structure ◽  
Hydrophobic Hydration ◽  
Micelle Formation ◽  
Aqueous Environment ◽  
Thermodynamic Quantities ◽  
Positive Contribution ◽  
Energy Of Hydration ◽  
Free Energy Of Hydration ◽  
Nonpolar Molecules

Many surfactants contain hydrocarbon moieties that are removed from their aqueous environment (‘dehydrated’) in, for example, adsorption and micelle formation. Hydrophobic hydration relates to the interactions between individual nonpolar solute molecules and water, and can be probed using thermodynamic quantities for the dissolution of dilute hydrocarbon vapours to form dilute aqueous solutions. Contrary to the simple expectation that the entropy of hydration of a nonpolar moiety should be positive (due to disruption of water structure), it is large and negative, giving a large positive contribution to the free energy of hydration. The hydration of nonpolar molecules in water leads to an attraction between the molecules in close proximity, which is termed hydrophobic bonding. Although the free energy of hydration of nonpolar groups in bulk aqueous solution is positive, the interaction free energy of nonpolar molecules/groups with interfacial water at an air/water interface is negative.

Temperature-dependence of electrochemical kinetic parameters: Electrode reaction of the Zn(Hg)/Zn(II) system

1982 ◽  
Vol 47 (5) ◽  
pp. 1433-1443 ◽  
Author(s):  
S. Kang ◽  
K. Matsuda ◽  
R. Tamamushi
Keyword(s):  
Aqueous Solutions ◽  
Temperature Dependence ◽  
Kinetic Parameters ◽  
Rate Constant ◽  
Activation Parameters ◽  
Electrode Reaction ◽  
Thermodynamic Quantities ◽  
Empirical Correlations ◽  
Square Wave ◽  
Different Temperatures

The electrochemical kinetic parameters of the D.M.E./Zn(II) electrode reaction in aqueous solutions containing perchlorate, nitrate, chloride and bromide ions were measured at different temperatures (5-50 °C) by the modified square-wave polarographic technique. The Arrhenius activation parameters and thermodynamic quantities of the electrode reaction were determined from the temperature dependence of the rate constant and conditional potential, respectively. Empirical correlations were observed between some pairs of kinetic and thermodynamic quantities.

Electrostatic and nonelectrostatic, conventional and unitary thermodynamic quantities of reaction. I. Metal–ligand reactions in aqueous solvent

1986 ◽  
Vol 64 (4) ◽  
pp. 780-784 ◽  
Author(s):  
Roberto Aruga
Keyword(s):  
Experimental Data ◽  
Complex Formation ◽  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Calculation Method ◽  
Thermodynamic Quantities ◽  
Pyridine Nitrogen ◽  
Aqueous Solvent ◽  
Ethereal Oxygen ◽  
Metal Ligand

A calculation method of the electrostatic and nonelectrostatic parts of thermodynamic quantities of reaction, previously proposed and applied to complex-formation reactions of aminic and carboxylic ligands, is applied, in the present work, to association reactions of several other ligands. In particular, to check its reliability, this method is applied to ΔG0, ΔH0, and ΔS0 data of literature for the formation of metal–anion pairs and for associations of metals with ligands containing pyridine nitrogen, ethereal oxygen, or thioethereal sulfur. Experimental data referring only to aqueous solutions are considered. The results obtained by this method are in agreement, in most cases, with those expected for the reactions examined. Therefore, it seems reliable and useful for a more significant interpretation of conventional thermodynamic parameters.

Pitzer and Thermodynamic Parameters of Triethanolamine and Glycine in Aqueous Saline Solutions

1993 ◽  
Vol 58 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Roberto Herrero ◽  
Isabel Brandariz ◽  
Sarah Fiol ◽  
Manuel Sastre de Vicente
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Equilibrium Constant ◽  
Thermodynamic Parameters ◽  
Thermodynamic Quantities ◽  
Pitzer Equations ◽  
Ionic Interaction ◽  
Ionic Strength Dependence ◽  
Strength Dependence ◽  
Saline Solutions

On the basis of the ionic strength dependence of the equilibrium constant (pK*) of thriethanolamine (TEA) and glycine, the ionic interaction parameters of the species involved in the equilibria TEAH+ ↔ TEA + H+ (for TEA), AH2+ ↔ AH + H+ and AH ↔ A- + H+ (for glycine) in aqueous solutions of KCl and KNO3, respectively, were determined using the Pitzer equations. Values of pK* were expressed on both the molarity and the molality scale at various temperatures and values of thermodynamic quantities ∆G0, ∆H0 and ∆S0 ascertained, for TEA.

scholarly journals Solubility of Ilaprazole in Various Alcohols in Temperature Range between (298.15 to 322.15) K

2015 ◽  
Vol 51 ◽  
pp. 155-159
Author(s):  
Shipra Baluja ◽  
Kapil Bhesaniya
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Empirical Equation ◽  
Dissolution Enthalpy ◽  
Temperature Range ◽  
Entropy Of Mixing ◽  
Gibb’S Free Energy ◽  
Semi Empirical

The solubility of Ilaprazole in methanol, ethanol, 2-propanol and n-butanol was measured using a gravimetrical method at temperature ranging from 298.15 K to 322.15 K. The results of these measurements were correlated with a semi empirical equation. Some thermodynamic parameters such as dissolution enthalpy, Gibb’s free energy, and entropy of mixing have also been calculated.

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