ChemInform Abstract: STANDARD POTENTIALS OF THE SILVER-SILVER IODIDE ELECTRODE IN AQUEOUS MIXTURES OF ETHANOL AND PROPAN-2-OL AT DIFFERENT TEMPERATURES. FREE ENERGIES AND ENTROPIES OF TRANSFER OF HYDROIODIC ACID AT 25°

1978 ◽  
Vol 9 (28) ◽  
Author(s):  
K. DAS ◽  
K. BOSE ◽  
A. K. DAS ◽  
K. K. KUNDU
Keyword(s):  
Silver Iodide ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Hydroiodic Acid ◽  
Different Temperatures ◽  
Silver Silver

Thermodynamics of transfer of glycine, diglycine, and triglycine from water to aqueous solutions of urea, glycerol, and sodium nitrate

1988 ◽  
Vol 66 (3) ◽  
pp. 461-468 ◽  
Author(s):  
Himansu Talukdar ◽  
Sibaprasad Rudra ◽  
Kiron K. Kundu
Keyword(s):  
Sodium Nitrate ◽  
Regular Function ◽  
Scaled Particle Theory ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Thermodynamics Of Transfer ◽  
Different Temperatures ◽  
Composition Profiles ◽  
Cavity Effect ◽  
Nitrate Solutions

Standard free energies [Formula: see text] and entropies [Formula: see text] of transfer of glycine (G), diglycine (DG), and triglycine (TG), from water to aqueous mixtures of glycerol (GL) and urea (UH) have been determined from solubility measurements at different temperatures. This was also extended to an ionic cosolvent system like aqueous sodium nitrate solutions for G and DG. The observed [Formula: see text] and [Formula: see text]–composition profiles, as well as those obtained after correcting for the "cavity effect" as estimated by scaled particle theory (SPT), were examined in the light of various interactions. The corrected [Formula: see text]and [Formula: see text] values show a regular function of the peptide chain length of the amino acids and impart useful information regarding the involved relative structural effects of these ionic and non-ionic cosolvents.

Behaviour of the silver-silver bromide and the silver-silver iodide electrodes in formamide at different temperatures

1975 ◽  
Vol 28 (8) ◽  
pp. 1657 ◽  
Author(s):  
UN Dash ◽  
B Nayak
Keyword(s):  
Silver Iodide ◽  
Silver Bromide ◽  
Thermodynamic Quantities ◽  
Standard Potential ◽  
Different Temperatures ◽  
Silver Silver ◽  
Good Agreement

From the e.m.f. measurements of the buffered cells of the type ��������������������� Pt, H2|HOAc(m1), KOAc(m2), KX(m3)|AgX-Ag the standard potentials of the Ag-AgX electrodes have been determined, in formamide, at nine different temperatures in the range 5-45�. The standard potentials of the Ag-AgX electrodes obtained at 25� are in good agreement with those obtained from the study of the cells ������������������ Ag-AgX|KX(m3), KOAc(m2), HOAc(m1), QH2-Q|Pt at 25�, where X is Br or I. The cell �������������������������Pt,H2|HBr(m)|AgBr-Ag has been further studied in this solvent at 25� with a view to having an independent check on these buffered cells for the standard potential of the Ag-AgBr electrode. The standard thermodynamic quantities (ΔG�, ΔH�, and ΔS�) for the corresponding cell reactions have been calculated from the e.m.f. data over the range, 5-45�.

Ion–ion–solvent interactions in aqueous ionic cosolvent systems. IV. Transfer energetics of water, p-nitroaniline, and benzoic acid from emf/solubility measurements at different temperatures in aqueous sodium nitrate solvent system

1988 ◽  
Vol 66 (3) ◽  
pp. 469-475
Author(s):  
Sibaprasad Rudra ◽  
Himansu Talukdar ◽  
Kiron K. Kundu
Keyword(s):  
Benzoic Acid ◽  
Sodium Nitrate ◽  
Solvent System ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Salting Out ◽  
Emf Measurements ◽  
Solvent Interactions ◽  
Different Temperatures ◽  
Composition Profiles

Autoionization constants (Ks) of aqueous mixtures of 1, 2, and 4 m sodium nitrate used as an ionic cosolvent system have been determined from emf measurements of the cell: Pt, H2 (g, 1 atm)/KOH (m1) KCl (m2), solvent/AgCl–Ag at five equidistant temperatures ranging from 15–35 °C. The standard free energies (ΔG0) and entropies (ΔS0) of autoionisation of the solvents were then evaluated from these data. Relative free energies (ΔG0) and entropies of (ΔS0)of autoionization of the solvents when coupled with the previously determined transfer free energies [Formula: see text] and entropies [Formula: see text] of H+ yielded [Formula: see text][Formula: see text],[Formula: see text] and [Formula: see text]. Values of [Formula: see text] and [Formula: see text] obtained after correcting for [Formula: see text], as well as [Formula: see text] and [Formula: see text]obtained after correcting the "cavity effect" and Born-type electrostatic effect suggests that while the "basicity" of the aqueous NaNO3 solutions decreases, the "acidity" more or less increases with NaNO3 concentration. The observed [Formula: see text]– and [Formula: see text]–composition profiles were also examined in the light of Kundu et al.'s four-step transfer process and the involved order–disorder phenomena, respectively, as proposed earlier.Standard free energies [Formula: see text] and entropies [Formula: see text] of transfer of p-nitroaniline (pNA) and benzoic acid (HBz) for the solvent system have also been determined from solubility measurements at different temperatures. The observed [Formula: see text]–and [Formula: see text]–composition profiles appear to reflect the salting-out effect of the salt and the [Formula: see text]–and [Formula: see text]–composition profiles confirm the applicability of either of these quantities rather than [Formula: see text], as a better structural probe both for aquo-ionic and aquo-organic solvents.

Deprotonation and transfer energetics of glycine in aqueous mixtures of urea and glycerol from emf measurements at different temperatures

1989 ◽  
Vol 67 (2) ◽  
pp. 315-320 ◽  
Author(s):  
Himansu Talukdar ◽  
Sibaprasad Rudra ◽  
Kiron K. Kundu
Keyword(s):  
Scaled Particle Theory ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Emf Measurements ◽  
Transfer Energetics ◽  
Galvanic Cells ◽  
Aqueous Urea ◽  
Different Temperatures ◽  
Composition Profiles ◽  
Reference Electrolyte

Deprotonation constants, Ka(RH2+) and Ka(RH±), of glycine (RH±) have been determined at five equidistant temperatures ranging from 15 to 35 °C by measuring the emf of galvanic cells comprising Pt/H2 and Ag–AgCl electrodes in aqueous mixtures of protophilic protic urea (UH) and protophobic protic glycerol (GL). Medium effects on deprotonation of the acid: [Formula: see text] have been dissected into transfer free energies [Formula: see text] and entropies [Formula: see text] of the species involved as obtained by measuring the transfer energetics [Formula: see text] of RH± from solubility measurements at different temperatures and of H+ based on tetraphenylarsonium tetraphenylborate (TATB) reference electrolyte assumption determined earlier. The [Formula: see text] values obtained after due correction from the cavity effect based on scaled particle theory (SPT) and electrostatic effects including Born and ion–dipole effects for the charged species involved in the two deprotonation equilibria enable better understanding of the solvent effect on the deprotonation constants. Moreover, the [Formula: see text]–composition profiles are found to exhibit similar characteristic maxima and minima as for simple cations and anions in these solvent systems, thus providing useful information on the structural characteristic of these cosolvents. Keywords: deprotonation energetics, glycine, aqueous urea, aqueous glycerol, EMF measurements.

Solubility study of mesalazine in the aqueous mixtures of a deep-eutectic solvent at different temperatures

2021 ◽  
pp. 116300
Author(s):  
Aynaz Zarghampour ◽  
Milad Moradi ◽  
Fleming Martinez ◽  
Salar Hemmati ◽  
Elaheh Rahimpour ◽  
...  
Keyword(s):  
Deep Eutectic Solvent ◽  
Aqueous Mixtures ◽  
Solubility Study ◽  
Different Temperatures
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