scholarly journals Viscometric and Conductometric Studies of Doxycycline Hyclate in Water, Aqueous Glycine and L-Alanine Solutions at Different Temperatures

2019 ◽  
Vol 31 (11) ◽  
pp. 2557-2566
Author(s):  
Shashi Kant Sharma ◽  
Poonam ◽  
Nisha Sharma
Keyword(s):  
Temperature Coefficient ◽  
Activation Entropy ◽  
Viscosity Data ◽  
Walden Product ◽  
Transfer Energy ◽  
Doxycycline Hyclate ◽  
Free Energy Of Activation ◽  
Conductance Data ◽  
Different Temperatures ◽  
Viscosity B Coefficient

To investigate the behaviour of doxycycline hyclate in water, aqueous glycine and aqueous L-alanine solutions, the viscometric and conductometric studies have been conducted at different temperatures. Viscosity data has been used to derive the Jones-Dole viscosity B-coefficient, temperature derivative of B-coefficient (dB/dT), viscosity B-coefficient of transfer (ΔtrB), free energy of activation of viscous flow per mole of solvent (Δμ1 o*) and solute (Δμ2o*) respectively, activation entropy (ΔS2o*) and activation enthalpy (ΔH2o*). Conductance data has been used to compute Walden product (Λm oηo) and temperature coefficient of Walden product (dΛmoηo/dT) for doxycycline hyclate in water, and in aqueous glycine and aqueous L-alanine solution. The positive values of B-coefficient, ΔtrB indicate the prevailing of hydrophilic-ionic interactions in the systems under examination. The negative values of dB/dT and positive values of temperature coefficient of Walden product infer structure maker tendency of doxycycline hyclate in water, and in aqueous glycine and aqueous L-alanine solution. Transfer energy parameters indicate the breaking of intermolecular bonds in transition state which means that formation of activated complex is unfavourable

Study of Intermolecular Interactions of CTAB with Amino Acids at Different Temperatures: A Multi Technique Approach

2019 ◽  
Vol 233 (2) ◽  
pp. 167-182 ◽  
Author(s):  
Anwar Ali ◽  
Nizamul Haque Ansari ◽  
Ummer Farooq ◽  
Shadma Tasneem ◽  
Firdosa Nabi
Keyword(s):  
Molar Volume ◽  
Intermolecular Interactions ◽  
Cetyltrimethylammonium Bromide ◽  
Complete Characterization ◽  
Viscosity Data ◽  
Viscosity Coefficients ◽  
Free Energy Of Activation ◽  
Different Temperatures ◽  
Amino Acid Solutions

Abstract The densities, ρ, viscosities, η and specific conductivities κ, of (0.0002, 0.0004, 0.0006 and 0.0008 m) CTAB in 0.1 m aqueous valine, leucine and isoleucine were measured at different temperatures. The measured data were used to calculate various useful thermodynamic parameters. A complete characterization of any mixture can be performed by means of these thermodynamic properties. The apparent molar volume, ϕv, partial molar volume, $\phi _v^0$ and partial molar isobaric expansibilities, $\phi _E^0,$ were calculated using density data. The viscosity data were analyzed using Jones–Dole equation to obtain viscosity coefficients, A- and B-, free energy of activation per mole of solvent, Δμ1°∗, and solute, Δμ2°∗, enthalpy, ΔH∗ and entropy, ΔS∗ of activation of viscous flow. Measuring the changes in these properties has been found to be an excellent qualitative and quantitative way to obtain information regarding the molecular structure and intermolecular interactions occurring in these mixtures. Various structure-making/breaking ability of solute (cetyltrimethylammonium bromide) in presence of aqueous amino acid solutions were discussed. In addition, fluorescence study using pyrene as a photophysical probe has been carried out, the results of which support the conclusions obtained from other techniques.

scholarly journals The Audio Frequency Conductance Study of Some Metal Succinate Salts in Aqueous Medium at Different Temperatures (Part I: Magnesium, Manganese (II), Barium and Copper Succinates)

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Kosrat N. Kaka ◽  
Anis A. Al-Najar ◽  
Wali M. Hamad
Keyword(s):  
Molar Conductance ◽  
Audio Frequency ◽  
Walden Product ◽  
Electrical Conductances ◽  
Conductance Data ◽  
Association Reaction ◽  
Different Temperatures ◽  
Quantitative Results ◽  
Strong Electrolytes ◽  
Modified Forms

The audio electrical conductances of aqueous solutions of magnesium, manganese II, barium, and copper succinates have been measured at various temperatures in the range of 298.15 K to 313.15 K, using an audio frequency conductance bridge. The evaluation of conductance data was carried out by minimisation technique using the theoretical equations of the complete and modified forms of Pitts (P) and Fuoss-Hsia (F-H), each a three-parameter equation, association constant (KA), molar conductance (Λm), and distance parameter (a). Quantitative results showed that these salts do not behave as “strong” electrolytes, and that their dissociations are far from complete. The abnormally low conductances of these electrolytes are not due to the presence of electrically neutral molecules but to the ion-pair formation. The Walden product values, as well as the standard thermodynamics functions (ΔH∘,ΔG∘,ΔS∘) for the association reaction at the four temperatures studied, have been evaluated.

Viscosities and thermodynamics of viscous flow of binary liquid mixtures of 2-(2-butoxyethoxy)ethanol with aniline and N-alkyl anilines

1992 ◽  
Vol 70 (10) ◽  
pp. 2645-2649 ◽  
Author(s):  
Paul Wiseman ◽  
Murray Heggie ◽  
Ramamurthy Palepu
Keyword(s):  
Liquid Mixtures ◽  
Viscosity Data ◽  
Specific Interactions ◽  
Molar Free Energy ◽  
Substituted Anilines ◽  
Ideal Behavior ◽  
Binary Liquid ◽  
Free Energy Of Activation ◽  
Different Temperatures ◽  
High Degree

Viscosities and densities of binary mixtures containing 2-(2-butoxyethoxy)ethanol with aniline and N-alkyl-substituted anilines have been determined at five different temperatures over the complete concentration range. Excess volumes, viscosities, and excess molar free energy of activation of flow were calculated and the departure from ideal behavior is explained on the basis of specific interactions between the components in these mixtures. McAllister's approach correlates the viscosity data with a significantly high degree of accuracy for all these systems.

Study of the Comparative Solvation Behaviour of Na+ and Cu+ Cations in Acetonitrile + N,N-Dimethylformamide Mixtures at 298.15 K

2004 ◽  
Vol 59 (9) ◽  
pp. 615-620 ◽  
Author(s):  
Dip Singh Gill ◽  
Hardeep Anand ◽  
J. K. Puri
Keyword(s):  
Molar Conductance ◽  
Viscosity Data ◽  
Extended Form ◽  
Composition Region ◽  
Conductance Data ◽  
Reference Electrolyte ◽  
B Coefficients

Viscosity and molar conductance of Bu4NBPh4, Bu4NClO4, [Cu(CH3CN)4]ClO4, NaClO4 and NaBPh4 have been measured in the concentration ranges 0.02 - 0.5 mol dm−3 and 0.0005 - 0.0065 mol dm−3 at 298.15 K in AN + DMF mixtures containing 0, 10, 20, 40, 60, 75, 80, 90, and 100 mol % DMF. The viscosity data have been analyzed by the extended form of the Jones-Dole equation in the form: (η/η0) = 1+AC1/2+BC+DC2 to evaluate B and D parameters and the conductance data by the Shedlovsky equation to evaluate Λo and KA values of the salts. Ionic viscosity B-coefficients (B±) and ionic molar conductances (λ◦ i) have been calculated by using Bu4NBPh4 as a reference electrolyte. Solvated radii (ri) for Na+, Cu+ and ClO4 − have been estimated by using Gill’s modification of Stokes’ law. The variation of B± and ri as a function of mol % DMF shows that both Na+ and Cu+ are highly solvated in AN + DMF mixtures over the entire composition region. The solvation passes through a maximum between 40 to 80 mol % DMF. Both Na+ and Cu+ are more strongly solvated between 40 to 80 mol % DMF. Cu+ is relatively more strongly solvated than Na+ in AN + DMF mixtures. ClO4 − shows poor solvation in AN + DMF mixtures.

Kinetics of Ion-Pair Effect of Aquation of Bromopentaammine Cobalt(III) Complex in Different Dicarboxylate Media

2011 ◽  
Vol 324 ◽  
pp. 166-169 ◽  
Author(s):  
Farah Zeitouni ◽  
Gehan El-Subruiti ◽  
Ghassan Younes ◽  
Mohammad Amira
Keyword(s):  
Free Energy ◽  
Solvent Effect ◽  
Compensation Effect ◽  
Ion Pairing ◽  
Reaction Rates ◽  
Ion Pair ◽  
Free Energy Of Activation ◽  
Different Types ◽  
Different Temperatures ◽  
Kinetics Of

The rate of aquation of bromopentaammine cobalt(III) ion in the presence of different types of dicarboxylate solutions containing tert-butanol (40% V/V) have been measured spectrophotometrically at different temperatures (30-600°C) in the light of the effects of ion-pairing on reaction rates and mechanism. The thermodynamic and extrathermodynamic parameters of activation have been calculated and discussed in terms of solvent effect on the ion-pair aquation reaction. The free energy of activation ∆Gip* is more or less linearly varied among the studied dicarboxylate ion-pairing ligands indicating the presence of compensation effect between ∆Hip* and ∆Sip*. Comparing the kip values with respect of different buffers at 40% of ter-butanol is introduced.

scholarly journals Study of Physical Properties for Sodium acetate with Water and Water - Acetone mixtures at Different Temperatures

2017 ◽  
Vol 27 (4) ◽  
Author(s):  
Ahmed Mohammed Abbas ◽  
Zainab Wajdi Ahmed ◽  
Alaa Fadhil Sulaiman ◽  
Issam AbdalKreem AbdalLatif
Keyword(s):  
Sodium Acetate ◽  
Apparent Molal Volume ◽  
Viscosity Data ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Solvent Interactions ◽  
Acetone Water ◽  
Thermodynamic Activation Parameter ◽  
Different Temperatures ◽  
Apparent Molal Compressibility

In this study binary and ternary solutions are prepared by using the sodium acetate concentrations (0.1, 0.125, 0.2, 0.25, 0.4, 0.5, 0.8, 1 M) in water and acetone –water mixtures .The important parameters such as apparent molal volume, the partial molal volume transfer,  apparent  molal compressibility, free energy of activation of viscous flow and thermodynamic activation parameter (enthalpy and entropy) determined of sodium acetate in water , 20%, 40% ,60% and 80% V/V acetone –water mixtures at 298.15K, 303.15K, and 308.15K from density and viscosity measurements espectively. The limiting apparent molal volumes and experimental slopes were derived from the Masson equation, have been interpreted in terms of solute–solvent and solute–solute interactions  respectively. The viscosity data were analyzed using theJones–Dole equation and the derived parameter B - coefficient has also been interpreted in terms of solute–solvent interactions in the solutions. 

Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

scholarly journals Kinetic Studies on Saponification of Poly(ethylene terephthalate) Waste Powder Using Conductivity Measurements

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Dilip B. Patil ◽  
Vijendra Batra ◽  
Sushil B. Kapoor
Keyword(s):  
Thermodynamic Parameters ◽  
Kinetic Studies ◽  
Frequency Factor ◽  
Reaction Rates ◽  
Reaction Rate Constant ◽  
Activation Entropy ◽  
Constant Frequency ◽  
Free Energy Of Activation ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Conductometric measurement technique has been deployed to study the kinetic behavior during the reaction of poly(ethylene terepthalate) (PET) and NaOH. A laboratory made arrangement with facility of continuous stirring was used to carry out experiments at desired temperature. With conductometry, the determination of kinetic as well as thermodynamic parameters becomes more simple and faster as compared to gravimetry. Chemical kinetics of this reaction shows that it is a second order reaction with reaction rate constant 2.88×10-3 g−1 s−1 at 70°C. The specific reaction rates of the saponification reaction in the temperature range at various temperatures (50–80°C) were determined. From the data, thermodynamic parameters such as activation energy, Arrhenius constant (frequency factor), activation enthalpy, activation entropy, and free energy of activation obtained were 54.2 KJ g−1, 5.0×106 min−1, 90.8 KJ g−1, -126.5 JK−1 g−1, and 49.9 KJ g−1, respectively.

Transcutaneous carbon dioxide and oxygen tension measured at different temperatures in healthy adults.

1985 ◽  
Vol 31 (10) ◽  
pp. 1611-1615 ◽  
Author(s):  
P D Wimberley ◽  
K Grønlund Pedersen ◽  
J Olsson ◽  
O Siggaard-Andersen
Keyword(s):  
Carbon Dioxide ◽  
Temperature Coefficient ◽  
Oxygen Tension ◽  
Carbon Dioxide Tension ◽  
Healthy Adults ◽  
Transcutaneous Oxygen ◽  
Transcutaneous Carbon Dioxide ◽  
Different Temperatures ◽  
Gas Measurements ◽  
Increasing Temperature

Abstract Transcutaneous carbon dioxide tension (tc-pco2) at 37, 39, 41, 43, and 45 degrees C, and transcutaneous oxygen tension (tc-po2) at 41, 43, and 45 degrees C were measured simultaneously in 10 healthy adults during hyperventilation and inhalation of O2/CO2 gas. Nine electrodes were applied to each subject: Five CO2 electrodes, one O2 electrode, and three combined O2/CO2 electrodes. The CO2 electrodes had negligible temperature coefficients in the calibration gases, but the O2 electrodes showed an increase in po2 of 4.5% per degree C. With skin application, tc-pco2 increased approximately 4% per degrees C between 37 and 45 degrees C, which is close to the anaerobic temperature coefficient of pco2 in blood. The tc-po2 increases on the skin with increasing temperature appeared to be more dependent on changes in blood flow in skin, but in the temperature range 43 to 45 degrees C, tc-po2 showed the expected decrease in the temperature coefficient with increasing po2. The correlation between transcutaneous and capillary pco2 was close at all transcutaneous electrode temperatures, even 37 degrees C, provided the skin was preheated (via the electrode) to 45 degrees C. For tc-po2, an electrode temperature of at least 43 degrees C was necessary to produce a reasonable correlation between tc-po2 and capillary po2. The combined O2/CO2 electrodes measured slightly higher pco2 values than the single CO2 electrodes, but there were no differences in po2 readings, stabilization time, imprecision, or electrode drift between the two electrode types. The imprecision (CV, %) of tc-pco2 and tc-po2 measurements was approximately twice that of the corresponding capillary blood-gas measurements.

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