scholarly journals Conductometric Study of Nimesulide in Aqueous Solutions of Hydrotropic Agents at Different Temperatures

2012 ◽  
Vol 9 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Chandravir S. Solanki ◽  
Paresh Mishra ◽  
Mahesh Kumar Talari ◽  
Minaketan Tripathy ◽  
Upendra N. Dash
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Sodium Benzoate ◽  
Sodium Salicylate ◽  
Molar Conductance ◽  
Association Constants ◽  
Sodium Bromide ◽  
Limiting Molar Conductance ◽  
Different Temperatures ◽  
Conductometric Study

Conductance values of nimesulide have been determined in water in 0.1, 0.2, 0.4, 0.6, 0.8, 1 and 2 mol dm-3aqueous solutions of hydrotropic agents (sodium benzoate, sodium salicylate, sodium bromide and nicotinamide) at temperatures 298.15, 303.15, 308.15 and 313.15 K. The conductance values have been used to evaluate the limiting molar conductance and association constants by means of Shedlovsky extrapolation technique. Thermodynamic parameters for the association process of nimesulide in aqueous solutions of hydrotropic agents have also been calculated.

scholarly journals Evaluation of the physical parameters of nano-sized tetrachlorosilane as an inorganic material a mixed solvent using Fuoss-Shedlovsky and Fuoss-Hsia-Fernández-Prini techniques

2020 ◽  
Vol 10 (4) ◽  
pp. 5741-5746
Keyword(s):  
Thermodynamic Parameters ◽  
Association Constant ◽  
Inorganic Material ◽  
Mixed Solvent ◽  
Electrical Conductance ◽  
Molar Conductance ◽  
Energy Of Activation ◽  
Physical Parameters ◽  
Walden Product ◽  
Limiting Molar Conductance

The electrical conductance of nano-sized tetrachlorosilane is measured in 50% mixed solvent of (absolute ethanol-H2O) at various temperatures. The Λ0 (limiting molar conductance) and the KA (association constant) are evaluated via using Fuoss-Shedlovsky (F-SH) and Fuoss-Hsia-Fernández-Prini (FHFP) theories. The standard thermodynamic parameters for association (ΔS°A, ΔH°A& ΔG°A), energy of activation (Ea), hydrodynamic radii (RH) and Walden product (Λ0 η0) are calculated for tetrachlorosilane. These various physical parameters for tetrachlorosilane are evaluated and discussed.

scholarly journals Thermodynamic Studies on Ion Association of Lithium Chloride and Lithium Nitrate in Acetonitrile + Water Mixed Solvents at Different Temperatures

2021 ◽  
Vol 34 (1) ◽  
pp. 230-234
Author(s):  
Lalrosanga ◽  
N. Mohondas Singh
Keyword(s):  
Lithium Chloride ◽  
Mixed Solvents ◽  
Ion Association ◽  
Molar Conductance ◽  
Lithium Nitrate ◽  
Mixed Composition ◽  
Water Solvent ◽  
Limiting Molar Conductance ◽  
Different Temperatures ◽  
Walden Products

The present study reports the ion association of lithium chloride (LiCl) and lithium nitrate (LiNO3) electrolytes in acetonitrile + water (AN+W) mixtures at 283.15 K to 311.15 K. Their limiting molar conductance (Λo), the association constant values (KA) for their different mole fractions, i.e. 0.0000, 0.0588, 0.1233, 0.1942, 0.2727, 0.3600, 0.4576, 0.5676, 0.6923, 0.8351 and 1.0000 have been evaluated using Shedlovsky technique. The KA and Walden products (Λoηo) for LiCl and LiNO3 salts have been calculated in the acetonitrile-water solvent at experimental temperatures. The calculated values qualitatively examined the possible nature of the solvent-solvent, their ion-ion, and ion-solvent and interactions of the two selected compounds mixed solvents of (acetonitrile + water). Then dependence of KA temperature has also been investigated to obtain the thermodynamic functions of different parameters, such as ΔGº, ΔSº, ΔHº and Ea, as a function of the mixed composition of the composition solvents AN+W (acetonitrile + water).

scholarly journals CONDUCTOMETRIC STUDY OF COMPLEX FORMATION BETWEEN 2,3-PYRAZINEDICARBOXYLIC ACID AND SOME TRANSITION METAL IONS IN METHANOL

2012 ◽  
Vol 20 (20) ◽  
pp. 43-50
Author(s):  
A.A. El-Khouly ◽  
E. A. Gomaa ◽  
S. E. Salem
Keyword(s):  
Complex Formation ◽  
Transition Metal Ions ◽  
Formation Constants ◽  
Molar Conductance ◽  
Association Constants ◽  
Absolute Methanol ◽  
Free Energies ◽  
Titration Curves ◽  
Conductometric Study ◽  
Complexation Reactions

The complexation reactions between CuCl2 CoCL2 and NiCL2 with 2,3-Pyrazinedicarboxylic acid in methanol (MeOH) at 313.15 K were studied by conductometric methods. The association constants, formation constants and Gibbs free energies were calculated from the conduclometric titration curves. On drawing the relation between molar conductance and the ratio of metal to ligand coflCentrations, different lines were obtained indicating the formation of 1: 1 and 2: 1 (M:L) stoichiometric complexes. The formation constants and Gibbs free energies of different complexes in absolute Methanol at 313.15 Kfollow the order:

scholarly journals Spectrophotometric and conductometric study of the complexation of N-salicylidene-2-aminophenol with Cu2+ in methanol + 1,4-dioxane binary solutions

2014 ◽  
Vol 79 (10) ◽  
pp. 1263-1277
Author(s):  
Rashmidipta Biswas ◽  
Dhiraj Brahman ◽  
Biswajit Sinha
Keyword(s):  
Stability Constants ◽  
Mixed Solvents ◽  
Molar Conductance ◽  
Binary Solvent ◽  
Complexation Reaction ◽  
Solvent Mixtures ◽  
Linear Behaviour ◽  
Different Temperatures ◽  
Conductometric Study ◽  
The Stability

The complexation reaction between N-salicylidene-2-aminophenol, abbreviated as SAP, with Cu2+ ion was studied in binary mixtures of methanol and 1,4-dioxane by using conductometric and spectrophotometric method at different temperatures. The stability constants (Kf) for the 1:1 complex, Cu2+-SAP, were calculated from computer fitting of absorbance and molar conductance data against various mole ratios (cM:cL or cL:cM) in different binary solvent mixtures. A non-linear behaviour was observed for the variation of logKf for the complex against the solvent compositions. Various thermodynamic parameters (?H, ?S and ?G) for the formation of Cu2+-SAP complex were determined from the temperature dependence of stability constants (Kf). The overall results showed that the complexation reaction is entropy driven and is affected by the nature and composition of the mixed solvents.

scholarly journals Studies on the Solute Solvent Interaction of Nimesulide in Aqueous Solutions of Hydrotropic Agents at Different Temperatures

2010 ◽  
Vol 7 (s1) ◽  
pp. S223-S230 ◽  
Author(s):  
Chandravir S. Solanki ◽  
Sushree Tripathy ◽  
Minaketan Tripathy ◽  
Upendra N. Dash
Keyword(s):  
Aqueous Solutions ◽  
Sodium Salicylate ◽  
Relative Viscosity ◽  
Partial Molar Volumes ◽  
Transition Theory ◽  
Solvent Interaction ◽  
Solvent Water ◽  
Different Temperatures ◽  
Density Values ◽  
Solute Solvent Interaction

The present study deals with experiments so as to highlight the solute (drug nimesulide) - solvent(water) interactions and related modifications in case of the presence of hydrotropic agents at different temperatures T(=298.15 to 313.15)K. Density and viscosity values of nimesulide have been determined in water in (0.1, 0.2, 0.4, 0.6, 0.8, 1 and 2) mol dm-3aqueous solutions of hydrotropic agents (sodium benzoate, sodium salicylate, sodium bromide and nicotinamide) at temperatures 298.15, 303.15, 308.15 and 313.15 K where as the solubility was studied at 308.15 K. From the density values, the limiting partial molar volumes and expansibilities have been calculated. The experimental viscosity values have been analyzed in terms of jones-dole equation and on the basis of transition theory for relative viscosity.

Study on the Inclusion Interactions of β-Cyclodextrin with Oleic Acid by Competitive Inclusion Method

2011 ◽  
Vol 130-134 ◽  
pp. 847-851 ◽  
Author(s):  
Xue Feng Xu ◽  
Ji Ju Guan ◽  
Rong Jun He
Keyword(s):  
Oleic Acid ◽  
Inclusion Complex ◽  
Thermodynamic Parameters ◽  
Association Constants ◽  
Grinding Wheel ◽  
Stoichiometric Ratio ◽  
Buffer Solution ◽  
Solution Ph ◽  
Inclusion Method ◽  
Different Temperatures

The grinding wheel will have a property of self-lubricating when the inclusion complexes of β-cyclodextrin (β-CD) and oleic acid are used as filler. The association constants and thermodynamic parameters of inclusion complex of β-CD and oleic acid were determined by competitive inclusion method in aqueous buffer solution (pH = 10.50, c = 0.025 mol/L) at different temperatures using phenolphthalein (PP) as a probe. Furthermore, the stoichiometric ratio of the complex was derived by equimolar series method. The results showed that the stoichiometric ratio of the complex was about 1:1 and the thermodynamic parameters of ΔG, ΔH and ΔS were all negative, which indicated that the formation of the inclusion complex was spontaneous, exothermic and enthalpy-driven. Thermogravimetric analysis revealed that the complex began to have a weight loss at 300°C and could withstand the hardening temperature of resin bond grinding wheel.

scholarly journals Physicochemical studies of binding of 4-methylumbelliferyl β-d-galactopyranoside to cold agglutinin

1989 ◽  
Vol 262 (1) ◽  
pp. 357-360 ◽  
Author(s):  
D Mitra ◽  
M Sarkar
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Binding Sites ◽  
Association Constants ◽  
Cold Agglutinin ◽  
Physicochemical Studies ◽  
Different Temperatures ◽  
Number Of Binding Sites ◽  
Enthalpy And Entropy ◽  
Quenching Phenomenon

The fluorescence of 4-methylumbelliferyl beta-D-galactopyranoside (MeUmbGalp) was quenched in the presence of cold agglutinin, showing that there was binding between MeUmbGalp and cold agglutinin. That binding was saccharide-specific. By using this quenching phenomenon, the association constants (Ka) of the binding of cold agglutinin at different temperatures (10 degrees C and 15 degrees C) to MeUmbGalp and also the number of binding sites were calculated. The Ka values were found to be 2.63 x 10(3) M-1 at 10 degrees C and 1.58 x 10(3) M-1 at 15 degrees C. Though there is a change in Ka values, the number of binding sites was calculated to be six at both temperatures (10 degrees C and 15 degrees C). From the Ka values the thermodynamic parameters (free energy, enthalpy and entropy) of the binding were derived, and analysis of the data indicated that the binding is spontaneous, exothermic and hydrophobic in nature.

Electrical Conductances of Tetrabutylammonium Bromide, Sodium Tetraphenylborate and Sodium Bromide in 2-Ethoxyethanol in the Temperature Range 35–50°C

2004 ◽  
Vol 218 (5) ◽  
pp. 599-610 ◽  
Author(s):  
Purushottam Haldar ◽  
Bijan Das
Keyword(s):  
Ion Pairs ◽  
Tetrabutylammonium Bromide ◽  
Molar Conductance ◽  
Sodium Bromide ◽  
Sodium Tetraphenylborate ◽  
Temperature Range ◽  
Electrical Conductances ◽  
Conductance Data ◽  
Limiting Molar Conductance ◽  
Concentration Equation

AbstractThe electrical conductances of the solutions of tetrabutylammonium bromide (Bu4NBr), sodium tetraphenylborate (NaPh4B) and sodium bromide (NaBr) in 2-ethoxyethanol have been reported at 35, 40, 45 and 50°C. The conductance data have been analyzed by the 1978 Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (KΛ) and the association diameter (R). The ionic contributions to the limiting molar conductances (Λ0) have been estimated using the “reference electrolyte” tetrabutylammonium tetraphenylborate (Bu4NPh4B). Appreciable ionic association was observed for all of these electrolytes which were found to exist in the form of solvent-separated ion-pairs in 2-ethoxyethanol. The tetrabutylammonium and tetraphenylborate ions are found to remain scarcely solvated whereas the sodium and bromide ions undergo substantial solvation in 2-ethoxyethanol medium in the temperature range investigated here.

Conductometric Study of Some Tetraalkylammonium Bromides in 2-Ethoxyethanol in the Temperature Range 35–50 °C

2004 ◽  
Vol 218 (9) ◽  
pp. 1129-1138 ◽  
Author(s):  
Purushottam Haldar ◽  
Bijan Das
Keyword(s):  
Ion Pairs ◽  
Molar Conductance ◽  
Tetraethylammonium Bromide ◽  
Temperature Range ◽  
Tetraalkylammonium Bromide ◽  
Conductance Data ◽  
Limiting Molar Conductance ◽  
Bromide Ion ◽  
Conductometric Study ◽  
Concentration Equation

AbstractThe electrical conductances of the solutions of four tetraalkylammonium bromide salts (R4NBr), namely tetraethylammonium bromide (Et4NBr), tetrapropylammonium bromide (Pr4NBr), tetrapentylammonium bromide (Pen4NBr) and tetraheptylammonium bromide (Hep4NBr) in 2-ethoxyethanol have been reported at 35, 40, 45 and 50 °C. The conductance data have been analyzed by the 1978 Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (KA) and the association diameter (R). The ionic contributions to the limiting molar conductance have also been estimated. Appreciable ionic association was observed for all of these electrolytes in 2-ethoxyethanol. The tetraalkylammonium ions (R4N+) were found to remain scarcely solvated in the present solvent medium within the temperature range investigated here. The solvation of the bromide ion in these tetraalkylammonium bromide is found to be weakened as soon as the ion-pairs are formed. An increase in the temperature results in a lower level of ion-pairing for each of these salts.

scholarly journals Thermodynamic and detailed kinetic study of the formation of orthophthalaldehyde-agmatine complex by fluorescence intensities

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Khémesse Kital ◽  
Moumouny Traoré ◽  
Diégane Sarr ◽  
Moussa Mbaye ◽  
Mame Diabou Gaye Seye ◽  
...  
Keyword(s):  
Complex Formation ◽  
Thermodynamic Parameters ◽  
Initial Rate ◽  
Reaction Medium ◽  
Standard Entropy ◽  
Step Size ◽  
Formation Reaction ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Complex Formation Process

Abstract The aim of this work is to determine the thermodynamic parameters and the kinetics of complex formation between orthophthalaldehyde (OPA) and agmatine (AGM) in an alkaline medium (pH 13). Firstly, the association constant (Ka) between orthophthalaldehyde and agmatine was determined at different temperatures (between 298 K and 338 K) with a step size of 10 K. Secondly, the thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°),and Gibbs energy (∆G) were calculated, where a positive value of ΔH° (+45.50 kJ/mol) was found, which shows that the reaction is endothermic. In addition, the low value of ΔS°(+0.24 kJ/mol) indicates a slight increase in the disorder in the reaction medium. Furthermore, the negative values of ΔG between −35.62 kJ/mol and −26.02 kJ/mol show that the complex formation process is spontaneous. Finally, the parameters of the kinetics of the reaction between OPA and AGM were determined as follows: when the initial concentration of AGM (5 × 10−6 M) is equal to that of the OPA, the results show that the reaction follows an overall 1.5 order kinetics with an initial rate of 5.1 × 10−7Mmin−1 and a half-life of 8.12 min. The partial order found in relation to the AGM is 0.8. This work shows that the excess of OPA accelerates the formation reaction of the complex.

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