Chaleur de dilution de solutions aqueuses d'acide polyacrylique, de son sel de sodium et de l'acide propionique

1971 ◽  
Vol 49 (24) ◽  
pp. 3935-3939 ◽  
Author(s):  
Jean-Pierre Cartier ◽  
Hubert Daoust
Keyword(s):  
Aqueous Solutions ◽  
Propionic Acid ◽  
Polyacrylic Acid ◽  
Sodium Polyacrylate ◽  
Heat Of Dilution ◽  
Concentrated Solutions ◽  
Sodium Salts ◽  
Structure Of Water ◽  
Calvet Microcalorimeter ◽  
Heats Of Dilution

With a Tian–Calvet microcalorimeter, heats of dilution at 25 °C have been measured for aqueous and acid (0.2 N HCl) solutions of polyacrylic acid and of propionic acid, and for aqueous solutions of the sodium salts of polyacrylic acid. The results are interpreted in terms of the change in structure of water resulting from the lengthening of the solute molecule. The heat of dilution of moderately concentrated solutions of sodium polyacrylate can be explained by the theory of Eigen and Wicke.

Chaleurs de dilution de solutions aqueuses d'acide polyméthacrylique et de ses sels de sodium et de rubidium

1976 ◽  
Vol 54 (12) ◽  
pp. 1853-1859 ◽  
Author(s):  
Hubert Daoust ◽  
Alain Lajoie
Keyword(s):  
Aqueous Solutions ◽  
Average Molecular Weight ◽  
Solute Concentration ◽  
Isobutyric Acid ◽  
Polymethacrylic Acid ◽  
Heat Of Dilution ◽  
Entire Concentration Range ◽  
Calvet Microcalorimeter ◽  
Heats Of Dilution ◽  
S Model

Heats of dilution of aqueous solutions of two polymethacrylic acid samples having a viscosity average molecular weight of 5000 (PMA-I) and 140 000 (PMA-II) respectively and of isobutyric acid (BA) have been measured at 25 °C using a Tian–Calvet microcalorimeter. The same measurements have been repeated in presence of HCl (0.2 N). Aqueous solutions of sodium and rubidium salts of PMA-I and II have also been investigated. Dilution of BA solutions is endothermic at high solute concentration and then becomes exothermic as concentration decreases and the presence of HCl does not affect the results. Dilution of PMA solutions is exothermic over the investigated concentration range in agreement with the results of Eliassaf and co-workers. PMA-I gives a more exothermic heat of dilution than PMA-II in the lower concentration range. The presence of HCl does not affect appreciably the results for PMA-II but it makes the dilution of PMA-I solutions less exothermic. The results are discussed in the light of Liquori et al.'s model for PMA chain which may adopt a globular or an extended solvated coil depending on solvent properties. Heats of dilution of aqueous solutions of sodium salts of both samples I and II are endothermic over the entire concentration range investigated whereas the heats of dilution of rubidium salts are exothermic.

scholarly journals XI. Heats of dilution of concentrated solutions

1915 ◽  
Vol 215 (523-537) ◽  
pp. 319-351 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Specific Heat ◽  
Final Concentration ◽  
Dilute Solution ◽  
Dilute Solutions ◽  
Concentrated Solutions ◽  
Specific Heats ◽  
Thermal Change ◽  
Heats Of Dilution ◽  
Concentrated Solution

Heats of dilution have been exhaustively studied by Prof. Julius Thomsen for a very large number of aqueous solutions.* His method chiefly consisted in taking some concentrated solution and diluting it considerably. The total amount of heat generated or absorbed in this process was thus found and quoted against the final concentration expressed in molecules of water to one molecule of solute. It is to be noted that during the process of dilution most of the thermal change occurs in the early stages, and that after the first ten molecules of water are added the total heat generated or absorbed increases but slightly. The probable reason for this procedure is, that the experimenter finishes the operation with a dilute solution, so that starting with various initial concentrations, he may need only a few specific heats of certain dilute solutions. It must be remembered that only the final .specific heat of the solution need be known in order to measure the heat generated.

Viscosity, electrical conductivity and density of the system ammonium nitrate-dimethyl sulphoxide

1984 ◽  
Vol 49 (5) ◽  
pp. 1109-1115
Author(s):  
Jindřich Novák ◽  
Zdeněk Kodejš ◽  
Ivo Sláma
Keyword(s):  
Electrical Conductivity ◽  
Aqueous Solutions ◽  
Ammonium Nitrate ◽  
Transport Properties ◽  
Calcium Nitrate ◽  
Dimethyl Sulphoxide ◽  
Present System ◽  
Empirical Equations ◽  
Concentrated Solutions ◽  
Nitrate Solutions

The density, viscosity, and electrical conductivity of highly concentrated solutions of ammonium nitrate in dimethyl sulphoxide have been determined over the temperature range 10-60 °C and the concentration range 7-50 mol% of the salt. The variations in the quantities as a function of temperature and concentration have been correlated by empirical equations. A comparison is made between the transport properties for the present system, aqueous solutions of ammonium nitrate, and calcium nitrate solutions in dimethyl sulphoxide.

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