The Influence of the Degree of Organization of Saturated Solutions on the Shape of the Solubility Isotherm

2001 ◽  
Vol 56 (12) ◽  
pp. 865-868 ◽  
Author(s):  
Jitka Eysseltová ◽  
Miroslav Ebert ◽  
Vladimír Zbranek
Keyword(s):  
Saturated Solution ◽  
Solubility Isotherm ◽  
Salt Hydrates ◽  
Solubility Isotherms ◽  
Saturated Solutions

AbstractSpecial features of solubility isotherms of salt hydrates have been observed, from which the evidence of strong organization of saturated solutions of hydrates may be deduced. Often observed low contents of the non saturating component in the eutonic solution limiting the crystallization branch of hydrated salts is put into connection with this result. The composition of the respective eutonic solutions exhibits a correlation with the hydration entropy of the ions present in the ternary saturated solution.

Competition Between Azido Cleavage and Triplet Nitrene Formation in Azidomethylacetophenones

2010 ◽  
Vol 63 (12) ◽  
pp. 1645 ◽  
Author(s):  
Ranaweera A. A. Upul Ranaweera ◽  
Yu Zhao ◽  
Sivaramakrishnan Muthukrishnan ◽  
Christopher Keller ◽  
Anna D. Gudmundsdottir
Keyword(s):  
Transition State ◽  
Density Functional ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Density Functional Theory Calculations ◽  
Laser Flash ◽  
Saturated Solution ◽  
Azido Group ◽  
Benzyl Radicals ◽  
Saturated Solutions

Photolysis of p- and m-azidomethylacetophenone (1a, 1b) in argon-saturated solutions yields predominantly imine 2a, 2b, whereas irradiation of 1a, 1b in oxygen-saturated solutions results in heterocycles 3a, 3b, aldehydes 4a, 4b and nitriles 5a, 5b. Density functional theory calculations place the energy of the first and second excited state of the triplet ketones (T1K and T2K) in 1a, 1b in close proximity to each other. The triplet transition state for cleaving the C–N bond in 1a, 1b to form azido and benzyl radicals 1aB, 1bB is located only 3 kcal mol–1 (1 kcal = 4.184 kJ) above T1K, indicating that azido cleavage is feasible. The calculations place the energy of the triplet azido group (TA) in 1a, 1b ∼25 kcal mol–1 below T1K; thus, this process is also easily accessible via energy transfer. Further, the transition state barrier for TA to expel N2 and form triplet nitrenes is less than 1 kcal mol–1 above TA in 1a, 1b. Laser flash photolysis of 1a, 1b reveals the formation of the triplet excited ketones of 1a, 1b, which decay to form benzyl radicals 1aB, 1bB and triplet alkylnitrenes. The triplet ketones and the benzyl radicals are quenched with molecular oxygen at rates close to diffusion, whereas the triplet nitrenes react more slowly with oxygen (∼5 × 105 M–1 s–1). We conclude that the triplet alkylnitrenes intercept the benzyl radicals to form 2 in argon-saturated solution, whereas the benzyl radicals are trapped to form 4 in oxygen-saturated solution; thus, the triplet nitrenes react with oxygen to form 3.

Saturated Solutions of M(NO3)2-H2O-CH3OH (M = Sr, Ba) Systems

1994 ◽  
Vol 59 (6) ◽  
pp. 1342-1348
Author(s):  
Mitko D. Stoev ◽  
Jóse M. A. Robledo
Keyword(s):  
Ir Spectra ◽  
Equilibrium Existence ◽  
Solubility Isotherms ◽  
Saturated Solutions

The solubility isotherms of the M(NO3)2 - H2O - CH3OH (M = Sr, Ba) systems at 25 °C have been studied. Crystallization fields of the equilibrium existence of the salts Sr(NO3)2 .4 H2O, Sr(NO3)2 and Ba(NO3)2 have been found. The structures of the saturated solutions on the basis of statistic calculations and IR spectra have been discussed.

Solubility in the Glycine-H3BO3-H2O System

1994 ◽  
Vol 59 (6) ◽  
pp. 1337-1341 ◽  
Author(s):  
Jitka Eysseltová ◽  
Jana Dosoudilová
Keyword(s):  
Boric Acid ◽  
Vapour Pressure ◽  
Pressure Measurements ◽  
Straight Line ◽  
Title System ◽  
Solubility Isotherms ◽  
Saturated Solutions

Solubility isotherms in the title system were measured at 0, 25, 50, and 70 °C. Regression straight line equations interrelating the solubilities of boric acid and glycine were derived. The activity of water in saturated solutions of the system at 25 °C was determined by vapour pressure measurements.

A Contribution to the Study of Ternary Saturated Electrolyte Solutions

1999 ◽  
Vol 54 (8-9) ◽  
pp. 485-487 ◽  
Author(s):  
J. Eysseltová ◽  
M. Ebert
Keyword(s):  
Phase Transitions ◽  
Ternary System ◽  
Ternary Systems ◽  
Electrolyte Solutions ◽  
Second Order ◽  
Saturated Solution ◽  
Concentrated Electrolyte Solutions ◽  
Common Ion ◽  
Solubility Isotherms

A quantity has been introduced, whose dependence on the composition along the branches of the solubility isotherms of ternary systems consisting of two salts with a common ion and water exhibits breaks, which can be explained by the introduction of a previously unobserved configuration of the ternary saturated solution. In the respective region, a saturated solution in a ternary system may undergo second-order phase transitions to achieve specific configurations that are not derived from the structure of the binary saturated solution of the particular solute. It is assumed that further study of this phenomenon could contribute to a better understanding of the processes occurring in concentrated electrolyte solutions.

Ionic Processes in Saturated Solutions of MgCl2·6H2O in Solutions of Other Divalent Metals

2001 ◽  
Vol 66 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Jitka Eysseltová
Keyword(s):  
Complex Formation ◽  
Copper Ions ◽  
Chloride Complex ◽  
The Other ◽  
Mercury Ions ◽  
Transfer Energy ◽  
Iron Cobalt ◽  
Usual Procedure ◽  
Solubility Isotherms ◽  
Saturated Solutions

Solubility isotherms of MgCl2·6H2O at 25 °C in solutions of chlorides of bivalent beryllium, calcium, manganese, iron, cobalt, zinc and mercury were treated by the hydration analysis. In addition to the usual procedure, the recently developed modified transfer energy Ξ was used to characterize the situation in saturated solutions. As a result, the following ionic processes were established in the saturated solutions under consideration: competition for water in solutions of MgCl2·6H2O containing beryllium and calcium chloride, complex formation in solutions of MgCl2·6H2O containing manganese, cobalt, zinc and mercury ions and formation of ions with heterogeneous coordination sphere in solutions of MgCl2·6H2O containing iron or copper ions. In the last case, the ability of the formed ions to crystallize from solution was found to be reduced in comparison with the other cases. Activity coefficients of MgCl2 were calculated along the solubility curves under consideration.

Calculation of the free Gibbs energy of phase transitions using solubility data. 1. The system Na2SO4-Na2Se04-H2O at 15 °C: Stable and metastable

2002 ◽  
Vol 74 (10) ◽  
pp. 1793-1800 ◽  
Author(s):  
Chr. Balarew
Keyword(s):  
Phase Transition ◽  
Gibbs Energy ◽  
Mixed Crystal ◽  
Distribution Coefficients ◽  
Mixed Crystals ◽  
Saturated Solution ◽  
Water Molecules ◽  
Free Gibbs Energy ◽  
Solubility Isotherms ◽  
Good Agreement

The solubility isotherms of the systems Na2SO4 ·10H2O–Na2SeO4·10H2O–H2O and Na2SO4·7H2O–Na2SeO4 ·7H2O–H2O have been investigated at 15 °C. It is established that discontinuous series of mixed crystals are formed in both systems. Two methods of calculation of the free Gibbs energy of phase transition at the interruption point of the solubility diagrams are used: (i) on the basis of the composition of the two mixed crystal types, which are in equilibrium with the saturated solution in the eutonic point of the system, and (ii) from the distribution coefficients between each of the mixed crystal phases and their saturated solution, using both experimentally obtained values and calculated distribution coefficients for ideal isomorphic mixing. The data found by the two methods exhibit very good agreement. It is established that the free Gibbs energy of the phase transition in the case of decahydrates is lower than in the case of heptahydrates. This fact is considered as a confirmation of the buffering action of water molecules with respect to the distortion of the crystal structures of the pure salts provoked by the formation of mixed crystals.

Hydration Analysis Based Calculation of Solute Activity Coefficients in Ternary Saturated Solutions

1994 ◽  
Vol 59 (11) ◽  
pp. 2351-2356 ◽  
Author(s):  
Jitka Eysseltová
Keyword(s):  
Activity Coefficient ◽  
Activity Coefficients ◽  
Wide Temperature Range ◽  
Model System ◽  
Saturated Solution ◽  
Solution Properties ◽  
System A ◽  
Starting Point ◽  
Solubility Isotherms ◽  
Good Agreement

Based on recently developed hydration analysis of solubility isotherms, a method for calculating activity coefficients of solute in ternary saturated solution is suggested. The method needs no adjustable parameters; it takes only solubility data and the value of the activity coefficient of the respective solute in its binary saturated solution under identical conditions as starting point. In the NaCl - KCl - H2O model system, a comparison between the calculated activity coefficients and those obtained by de Lima and Pitzer from solution properties and from the solubility shows a good agreement over a wide temperature range.

Treatment with a saturated solution of potassium permanganate for some dermatoses

1934 ◽  
Vol 30 (10) ◽  
pp. 1015-1016
Author(s):  
I. N. Olesov ◽  
G. G. Kondratiev ◽  
P. E. Evdokimov
Keyword(s):  
Potassium Permanganate ◽  
Clinical Studies ◽  
Skin Diseases ◽  
Experimental Studies ◽  
Large Percentage ◽  
Saturated Solution ◽  
Unexpected Result ◽  
Concentrated Solutions ◽  
Clinical Observations ◽  
Saturated Solutions

In search of the easiest, cheapest and most effective method of treating pyoderma, we tested a number of different ointments and solutions. After experimental studies, we settled on concentrated solutions of KMnO4 and in clinical studies we got a completely unexpected result. Lubrication with saturated solutions of skin areas affected by pyoderma does not cause any unpleasant subjective sensations and quickly restores the damaged areas of the epidermis. After a number of clinical observations of the action of KMnO4 on pyodermic skin diseases, we expanded the scope of our observations and began to treat dyshydrosis, psoriasis, eczema and other dermatoses with this method, and in a large percentage of cases we obtained a brilliant effect.

Sign in / Sign up

Export Citation Format

Share Document