Potassium chloride dielectric constant

D. L. Chapman, for potassium tri-iodide. 0. Gropp measured the effect of temp, on the conductivity of solid and frozen soln. of sodium iodide. For the effect of press, on the electrical properties, vide alkali chlorides. A. Reis found the free energy for the separation of the ions of K1 to be 144 lrilogrm. cals, per mol. for iN al, 158 Lil, 153 and for HI, 305. S. W. Serkofi 35 measured the conductivity of lithium iodide in methyl alcohol P. Walden, of sodium iodide in acetonitrile P. Dutoit in acetone, benzonitrite, pyridine, acetophenone. J. C. Philip and H. R. Courtman, B. B. Turner, J. Fischler, and P. Walden of potassium iodide in methyl or ethyl alcohol J. C. Philip and H. P. Courtman in nitromethane P. Dutoit in acetone. H. C. Jones, of rubidium iodide in formamide. S. von Lasczynsky and S. von Gorsky, of potassium and sodium iodides in pyridine. A. Heydweiller found the dielectric constants of powdered and compact potassium iodide to be respectively 3 00 and 5 58. 

A number of eases of satisfactory agreement with theoretical requirements have been found in methyl alcohol solutions this is particularly the case for the chlorides and thiocyanates of the alkali metals. Other electrolytes, such as nitrates, tetralkyl-ammonium salts and salts of higher valence types, however, exhibit appreciable deviations. These discrepancies become more marked the lower the dielectric constant of the medium, especially if the latter is noii-hydroxylic in character. The conductance of potassium iodide has been determined in a number of solvents at 25 and the experimental and calculated slopes of the plots of A against Vc arc quoted in Table XXV,... 

The measurements of the Debye-Falkenhagen effect are generally made with reference to potassium chloride the results for a number of electrolytes of different valence types have been found to be in satisfactory agreement with the theoretical requirements. Increase of temperature and decrease of the dielectric constant of the solvent necessitates the use of shorter wave lengths for the dispersion of conductance to be observed these results are also in accordance with expectation from theory. 

The transport number of the anion of potassium sulphate from about N- to N-eoln. lies between 0 50Q-0 506 and the temp, coelf. for the conductivity of O OIN-soln., 0 0223 (18 -26 ) and for sodium sulphate soln., 0 0240 (22 ). The potential difference of a normal soln. of sodium sulphate against 10 per cent. H2SO4 is —0 148 volt ordinary commercial nitric acid, —0 677 volt against 60 per cent. KOH, 0 154 volt and is inappreciable against 33 per cent. ZnS04, soln. of CUSO4. G. M. J. McKay measured the transport number with mixed soln. of potassium chloride and sulphate. A. Heydweiller found respectively 3 34 and 5 87 for the dielectric constant of powdered and compact potassium sulphate and C. B, Thwing, 6 45 for potassium sulphate. 

Formic acid melts at 8.40°C and has a cryoscopic constant Ac = 1.932 K kg mol". These results of J. Lange were obtained by a Beckmann cooling-curve technique in which a differential apparatus gave values of freezing point depression for which a precision of 0.0001 K was reported. Formic acid has a dielectric constant of 58.5 at 16°C and results for potassium chloride, potassium picrate and tetramethylam-monium chloride were fitted to an extended Debye-Hiickel equation for completely dissociated electrolytes. Tetramethylammonium chloride showed the smallest deviation from the limiting law and this was ascribed to the affinity of the organic cation for the solvent. 

Similar solvent properties are exhibited by acetyl- or benzoyl chloride " as solvents, while phosphorus oxychloride , phenylphosphonic dichloride and selenium oxychloride have somewhat higher donor numbers. They are still useful for the preparation of various complex chlorides, in particular selenium oxychloride, which has also a reasonable dielectric constant. Ionic compounds such as potassium chloride can be dissolved with the rapid formation of chloro-complexes ... 

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