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salt, while sodium nitrate has a positive partial molal volumc., and probably is iiot solvated. hl 1 I1 ‘These kindings are in accord with the results of I / ‘.: IO (I 1 ‘i Ill 2 (1 4; 1 Y 10 +;ti tliis research i i i a very similar solvent, and throw . . t:XIOi GI ~ ( J I I I V light 011 tlic mechanism of the ionization 1 x lo-‘ 0 t’J2 i ill) 0‘2 process in solution. Since only an extremely .{ x 10 5 5.; sinali fractioii of the litliiuni salt present is 111 5 x 10 b 5x t l w f o r i n of single ioii$ i i i a solution of ordinary Li(lOh .h9 .. 2 ~ l I l I l ~l concciitratioii such as those measured by Kelso potassium ioditle, lithium iodide, with lithiuin aiid Velsing, the large negative partial molal iodide having the largest coefficient, ‘This iii bolume observed must be caused by the ions in turn means that A H for lithium iodidc has thc combination, rather than those existing as single largest negative value, indicating either that the 1011s. If these iregativ~partial molal volumes entropy of orientation of the solvent is greater €or are to he interpreted as indicating solvatioti, this ion or that the free energy of ionizatioii is then the ions iri the ioii pairs are solvated and smaller. Bent and Keevi16 point out from their the greater dissociatioii of tlic lithium salt is duc somewhat meager data oil ether solutions that to the greater separatioii of the ions in the ioiiwhile A F varies somewhat with the distance of pairs, resulting iu a weakening of the coulombic closest approach of the ioiis, the cntropy change force between them. is relatively constant. If this is generally true, ’l‘hc author wishcs to thank Professors H. E. then the variation in AI1 IS due to a differelice Hrnt and Grinncll Jones for many suggestions in AF, rather than AS. Since the free energy of and helpful criticisms. ionization decreases with illcreasing 1 o n sire, that is, larger salts arc more easily iouized, it Summary follows that the lithium ion has the largest ionic 1. The conductances of dilute solutions of radius with the potassium ion iiext, as tlrduced sodium, potassium and lithium iodides in dipreviously. This again probably means that tlic methylamine have been measured. lithium ion is solvated. 2 . The results are qualitatively in accord with In a recent article,“ Kelso and Felsing have the Kraus and Fuoss theory. reported finding negative partial molal volumes 3 . It was found that the lithium ion is probably for lithium chloride in niethylaruine solutions. solvated by dimethylamine. This probably indicates sonit3 solvatioii of this KNOXCOLLEGE rARI t
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