Introduction Magnesium sulfate is an archetypal 2-2 salt that plays a central role in defining the characteristics of higher valent electrolyte solutions and its solution has been widely used to test various theories...Introduction Magnesium sulfate is an archetypal 2-2 salt that plays a central role in defining the characteristics of higher valent electrolyte solutions and its solution has been widely used to test various theories of strong electrolyte behavior and to develop models of ion association in solution. Up to now, the ion pairs of magnesium sulfate in an aqueous solution have been widely investigated by using different experimental techniques, such as conductometry , cryoscopy potentiometry solubility and Raman spectrometry. However, to our knowledge, no measurement of the standard association constant of the ion pairs, [ MgSO4 ]^0 in a glucosewater mixed solvent is available.展开更多
First and second thermodynamic dissociation constants of glycine at five temperatures from 278.15K to 318,15K in {14.926 mass％ urea + water} mixed solvent have been determined from precise emfmeasurements of hydrogen...First and second thermodynamic dissociation constants of glycine at five temperatures from 278.15K to 318,15K in {14.926 mass％ urea + water} mixed solvent have been determined from precise emfmeasurements of hydrogen-silver chloride electrodes in two cells, (A) and (B), without liquid junc- tion, by the new method of polynomial approximation proposed on the basis of Pitzer's electro- lytic solution theory in our previous papers, as compared with traditional extrapolation on the basis of the extended Debye-(?) equation. The results obtained from both methods are in agreement within experimental error. The thermodynamic quantities △G^0, △H^0, △S^0 and △C_p^0 were derived from the dependence of pK^0 values on temperature, and pK_1 = 367.60 (K / T) - 0.3973 + 3.108× 10^(-3) (T/K), whereas pK_2=2028.77 (K/ T)+ 2.8791-2.110×10^(-3) (T/K). The results have been discussed in terms of the solute-solvent interaction and have been compared with those results in water and in other mixed solvents.展开更多
文摘Introduction Magnesium sulfate is an archetypal 2-2 salt that plays a central role in defining the characteristics of higher valent electrolyte solutions and its solution has been widely used to test various theories of strong electrolyte behavior and to develop models of ion association in solution. Up to now, the ion pairs of magnesium sulfate in an aqueous solution have been widely investigated by using different experimental techniques, such as conductometry , cryoscopy potentiometry solubility and Raman spectrometry. However, to our knowledge, no measurement of the standard association constant of the ion pairs, [ MgSO4 ]^0 in a glucosewater mixed solvent is available.
基金Project supported by the National Natural Science Foundation of China
文摘First and second thermodynamic dissociation constants of glycine at five temperatures from 278.15K to 318,15K in {14.926 mass％ urea + water} mixed solvent have been determined from precise emfmeasurements of hydrogen-silver chloride electrodes in two cells, (A) and (B), without liquid junc- tion, by the new method of polynomial approximation proposed on the basis of Pitzer's electro- lytic solution theory in our previous papers, as compared with traditional extrapolation on the basis of the extended Debye-(?) equation. The results obtained from both methods are in agreement within experimental error. The thermodynamic quantities △G^0, △H^0, △S^0 and △C_p^0 were derived from the dependence of pK^0 values on temperature, and pK_1 = 367.60 (K / T) - 0.3973 + 3.108× 10^(-3) (T/K), whereas pK_2=2028.77 (K/ T)+ 2.8791-2.110×10^(-3) (T/K). The results have been discussed in terms of the solute-solvent interaction and have been compared with those results in water and in other mixed solvents.
