scholarly journals ON GUAIACOL SOLUTIONS

1934 ◽  
Vol 17 (4) ◽  
pp. 549-561 ◽  
Author(s):  
Theodore Shedlovsky ◽  
Herbert H. Uhlig

1. Measurements on the densities, viscosities, dielectric constants, and specific conductances of pure anhydrous and water-saturated guaiacol at 25°C. are reported. 2. The solubility of water in guaiacol at 25°C., and its effect on the electrical conductivity of a sodium guaiacolate solution is given. 3. Electrical conductivity measurements are reported on solutions of sodium and potassium guaiacolates in water-saturated guaiacol at 25°C. 4. The decrease of electrical conductivity with increasing concentration for these salts is explained on the basis of an ionic equilibrium combined with the interionic attraction theory of Debye and Hückel. 5. The limiting equivalent conductances of sodium and potassium guaiacolates in water-saturated guaiacol at 25°C., the corresponding limiting ionic mobilities, and the dissociation constants are computed from the conductivity measurements. The salts are found to be weak electrolytes with dissociation constants of the order of 5 x 10–6.

1934 ◽  
Vol 17 (4) ◽  
pp. 563-576 ◽  
Author(s):  
Theodore Shedlovsky ◽  
Herbert H. Uhlig

1. Measurements are reported on the distribution of sodium and potassium guaiacolates between guaiacol and water at 25°C. 2. The variation of the partition coefficients with the concentration is explained with the aid of the Debye-Hückel interionic attraction theory and the assumption that the salts are strong electrolytes in water and weak electrolytes in guaiacol. 3. The dissociation constants of sodium and potassium guaiacolates in guaiacol previously computed from electrical conductivity determinations are shown to be in agreement with the corresponding values obtained from the distribution measurements. 4. From theoretical considerations an equation is derived with which it is possible to predict the magnitude of the limiting partition coefficients from the dielectric constants of the solvents, the size of the solute ions, and the temperature.


1960 ◽  
Vol 38 (8) ◽  
pp. 1363-1370 ◽  
Author(s):  
R. H. Flowers ◽  
R. J. Gillespie ◽  
E. A. Robinson

Acid–base reactions in the solvent sulphuric acid are discussed. Such reactions are conveniently studied by electrical conductivity measurements. A relation between the composition at which the conductivity has a minimum value and the strengths of the acid and base is derived. Values of the dissociation constants of acids and bases obtained in this way are shown to be in good agreement with values obtained by other methods.


1998 ◽  
Vol 53 (10-11) ◽  
pp. 903-908
Author(s):  
Shin’ichi Ishimaru ◽  
Miho Yamauchi ◽  
Ryuichi Ikeda

Abstract We observed 1H and 2H NMR spectra, 1H NMR spin-lattice relaxation times, and electrical con-ductivities of water-saturated and anhydrous tetramethylammonium(TMA)-saponites between 100 and 415 K. The very weakly bound cations produced narrow 1H and 2H NMR lines observed in both specimens down to 150 K. The temperature dependence of the 'H NMR spin-lattice relaxation times in the water-saturated and anhydrous samples gave asymmetric minima attributable to the heteroge-neous overall rotation and self-diffusion of the cations. The inhomogeneity of the cationic motions in the anhydrous TMA-saponite was greater than in the water-saturated one. From measurements of the electrical conductivity of anhydrous TMA-saponite a large anisotropic cation-diffusivity was concluded.


2020 ◽  
Vol 61 (1) ◽  
pp. 81-85
Author(s):  
Vera A. Petrukhina ◽  
◽  
Pavel I. Fedorov ◽  
Ksenia A. Konnova ◽  
Maria V. Yakimova ◽  
...  

Earlier, we studied the electrical conductivity of inorganic salts in a number of alcohols (ethanol, propanol-2, and butanol-1) at room temperature and found that alcoholic solutions of inorganic salts are weak electrolytes. It is known that an increase in the temperature of salt solutions leads to an increase in electrical conductivity due to an increase in the mobility of their ions in the solvent medium. To study the temperature dependence of the electrical conductivity of aqueous solutions of electrolytes, we proposed an approach based on the study of the effect of temperature on the equivalent electrical conductivity of solutions at infinite dilution λ∞. Using this approach, we studied the electrical conductivity of aqueous solutions of a number inorganic salts (nitrates, acetates, and phosphates), carboxylic acids, and amino acids as a function of temperature. It was found that for these solutions the dependence λ∞(Т) is described by the exponential Arrhenius equation λ∞ = Аexp(-E/(RT)). This equation was used to describe the temperature dependence of the ultimate equivalent conductivity for solutions of a number of inorganic salts (calcium and nitrate calcium, cadmium, lithium and potassium iodides, chloride, iodide and ammonium nitrate, silver nitrate and sodium bromide) in ethanol. This article investigated and demonstrated the possibility of describing the experimental data λ∞(Т) for solutions of ethylates, propylates and isopropylates of sodium and potassium in the corresponding alcohols (ethylates in ethanol, propylates in propanol, isopropylates in isopropyl alcohol) using the same equation.


1991 ◽  
Vol 18 (3) ◽  
pp. 611-627 ◽  
Author(s):  
Marta L. Fiorotto ◽  
William J. Klish

2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.


2019 ◽  
Vol 104 (12) ◽  
pp. 1800-1805
Author(s):  
George M. Amulele ◽  
Anthony W. Lanati ◽  
Simon M. Clark

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.


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