Methyl alcohol conductivity

The tinctura iodi of the British Pharmacopoeia is a soln. of half an ounce of iodine, and a quarter of an ounce of potassium iodide in a pint of rectified spirit. P. Wantig found the mol. ht. of soln. —1 941 Cals., and S. U. Pickering —1 714 per 880 mol. of ethyl alcohol. C. Lowig found that alcoholic tincture of bromine is slowly decomposed in darkness, rapidly in light. Alcoholic soln. of iodine, according to H. E. Barnard, are stable in light and in darkness, but according to J. M. Eder they decompose 1000 times more slowly than chlorine water under similar conditions T. Budde has shown that hydriodic acid, acetic ester, and aldehyde are formed, and the electrical conductivity of the soln. increases. J. H. Mathews and E. H. Archibald and W. A. Patrick found a freshly prepared AT-soln. to have an electrical conductivity of 2 4 XlO-6 reciprocal ohms and a sat. soln., 1 61 X10 4 reciprocal ohms at 25°. The decomposition is accelerated by the presence of platinum. The heat of soln. decreases with concentration from —7 92 to —7 42 cals, respectively for dilute and sat. soln. in methyl alcohol, and likewise from —4 88 to —5 22 cals, for similar soln. in ethyl alcohol. The solubility of iodine in aq. soln. of propyl alcohol is not very different from that in ethyl alcohol. 

According to W. Herz and G. Anders,32 sat. soln. of potassium bromide in water and methyl alcohol at 25° contain respectively 4 708 and 0 142 mols. per litre the soln. have respectively the sp. gr. 1 37927 and 0 80493 referred to water at 4° the relative viscosities, 1 062 and 0 697, the relative eq. conductivities 91 3 and 57 9 and the specific conductivities. 0 4297 and 0 00825. P. Dutoit and A. Levier have measured the conductivities of soln. in acetone, and hence inferred that in this solvent potassium bromide is much less ionized than potassium iodide. 

Ammonium bromide dissolves in various organic solvents. Ethyl alcohol at 15° dissolves 2-97 per cent, of the salt at 19°, 3 12 per cent. and at 78°, 9 50 per cent. Methyl alcohol at 19° dissolves 11-1 per cent. and ether (sp. gr. 0729) dissolves 0123 grm. of salt per 100 grms. of solvent. G. Tammann and W. Hirsch-berg have measured the sp. gr. of alcoholic soln. and measurements on the lowering of the f.p. and the electrical conductivities by G. Carrara and by H. C. Jones and C. L. Lindsay show that the salt is considerably ionized in these soln.—vide alkali bromides. Similar remarks apply to soln. of ammonium bromide in acetone by P. Dutoit and A. Levier, and in formic acid by H. Zanninovich-Tessarin. In the vol. n. 2 q... 

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. 

O. Humburg measured the conductivity in methyl alcohol soln. 

Ljaschenko and Stepko have studied the decrease of the electrical conductivity of very thin CU2O films after these films had chemisorbed methyl alcohol, ethyl alcohol, acetone, and water vapor. Engell (18) has explained this decrease of conductivity by extending the explanation given above to the chemisorption on thin films whose total thickness is less than the thickness of the boundary layer. If is the conductivity before the chemisorption of any of the vapors listed above, the mean longitudinal conductivity after the chemisorption has taken place, and ifiH) then Ak is proportional to the number of the electron... 

Comparison of the electrical conductivities of chromium penta-phenyl hydroxide, sodium hydroxide and ammonia in absolute methyl alcohol and in methyl alcohol-water solution, shows that the former is a very strong base. In aqueous methyl alcohol solution the chromium compound does not appear to approach the limiting value with increasing dilution. The ultra-violet absorption spectrum examined in absolute ethyl alcohol solution resembles that of chromic acid and the dichromates, but the absorption is noticeably greater in the case of the organic compound. 

Chromium tetraphenyl iodide in methyl alcohol or moist chloroform is treated with silver oxide, or the iodide is subjected to electrolysis, using an alcohol solution with a platinum or mercury cathode and a rotating silver anode. One molecule of wTater is removed by drying over calcium chloride. The base forms orange-coloured plates, M.pt. 104° to 105° C. when placed in a bath previously heated to 95° C. It dissolves readily in water or alcohols, is sparingly soluble in chloroform, insoluble in benzene or ether. Measurements of its conductivity in aqueous solution show that it is comparable in strength with the alkali hydroxides, whilst comparative tests in methyl alcohol solution show that it is a stronger base than chromium pentaphenyl hydroxide. It may readily be converted into the chloride, bromide and iodide. 

Fig. 4.101. Change in the equivalent conductivity of some alkali sul-focyanates with concentration in methyl alcohol.

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,... 

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