Equations are derived for estimating phenomenological coefficients and diffusion coefficients for two classes of ternary systems: class I, containing only strong electrolytes as solutes, and class II, containing both weak and strong electrolytes as solutes. The approximate equations derived relate each of the four phenomenological coefficients for a ternary system to the concentrations and limiting equivalent conductivities of the ions in the system.From estimates of the phenomenological coefficients and from either known or estimated values for the chemical potential derivatives, the four diffusion coefficients for the system can be calculated. Estimated values for the coefficients are compared with observed values in the literature for four systems: H20-NaCl-KCl, H20-LiCl-KCl, H20-LiCl-NaCl, and H20-Na2S04-H2S04. Agreement between estimated and observed values is good for the first three systems but poor for the last system. From these comparisons the concentration range of validity of approximations made during the derivatives is inferred.(5) G.
viewed by the spectrophotometer through a rotating can (~10,000 r.p.m.) type of shutter. For both fluorescence and phosphorescence the exciting light was of wave lengths 2900-3000 A.To measure the lifetime of phosphorescence, the cyclopentanone in a dilute glass at 77 °K. was excited by a light flash of short duration. By means of a Corning 7-54 filter the exciting light was limited to the region 2400-4000 Á., while the emitted light that reached the photomultiplier was limited to wave lengths longer than 4600 A. by a 4-65 filter. The flash triggered one sweep by a fast oscilloscope connected to the photomultiplier. Under identical conditions, the pure glassy solvent showed no emission, while a glass containing cyclopentanone (0.1 M) showed an easily measurable luminescent decay with a lifetime of 1.1 X 10~3 sec.If the fluorescence spectrum is normalized to the absorption intensity and plotted on a wave number scale, the resultant spectra show an approximate "mirror image symmetry." The maximum of the fluorescence band lies at 4000-4100 Á. and is structureless. Dilute solutions (10-2-10~8 M hexane, 25°) were used, to avoid self-quenching or re-absorption of fluorescence or the localization of the fluorescence near the incident face of the cuvette. Any of these reasons would account for the failure to observe fluorescence in the pure liquid.3We found the phosphorescence, like the fluorescence of cyclopentanone, to be without structure; this probably is due in some measure to the low resolving power of the spectrophotometer. The phosphorescence maximum (4400-4500 Á.) and the lifetime of phosphorescence (1.1 X 10~3 sec.) of cyclopentanone are quite reasonable for an aliphatic ketone under these conditions. McClure7 reported an average phosphorescence frequency of 23,000 cm.-1 for the aliphatic ketones and lifetimes of 0.6 X 1CU3 sec. (acetone), 1.26 X 10~8 sec. (diethyl ketone), and quite similar lifetimes for the triplet states of other aliphatic ketones under conditions equivalent to those described above. The observed phosphorescence and decay time therefore are ascribed to the triplet state of cyclopentanone. (7) D, 8. McClure, J. Chem.IT, 905 (J949).
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