Isotope separation factors of seventeen two-phase equilibrium systems for lithium isotope enrichment have been determined. In all cases, lithium amalgam was used as one of the lithium-containing phases and was equilibrated with an aqueous or organic phase containing a lithium compound. In all systems examined, isotopic exchange was found to be extremely rapid, and 6Li was concentrated in the amalgam phase. The isotopic separation factor for the LiOH(aqueous) vs Li(amalgam) system has been studied as a function of temperature from −2 to 80 °C. The values obtained have been compared with the ’’electrolysis’’ and exchange separation factors given in the literature. The two-phase systems, LiCl(ethylenediamine) vs Li(amalgam) and LiCl(propylenediamine) vs Li(amalgam), have been studied, and the isotopic separation factors have been determined as functions of the temperature. The factors for the two systems have been found to be substantially the same (within limits of the errors involved) over the temperature range studied (0 to 100 °C) as those for the aqueous system. The isotopic separation factors for the seventeen systems have been tabulated, and correlations have been drawn that show the salt and solvent effects upon the values obtained.
The theory of ring current transients at a ring-disc electrode has been tested for Fe(CN)z-/ Good agreement between theory Fe(CN):-and Br2/Br-systems at three different rotation speeds. and experiment has been found. This paper compares observed ring current transients with the theory presented in previous papers.l* In these experiments the disc current was stepped at t = 0 from one value, iD,o, to another value, iD,OO. This changed the flux of an electrogenerated intermediate at the disc electrode and the consequent variation of the current with time at the ring electrode was measured.From eqn (5) in ref. (2), Nt = -N K f where nD iR,t-iR,O nR iD,co-zD,O . Y N , = --p = -l/o for a simple step in the disc flux and K is replaced in N, by d. special case where iD,-, = iR,o = 0. Thus one obtains for 7-and > 1 This equation is identical with eqn (1.6) of ref. (1); this reference considers the N , N ( N / N 2 ) [ N -fl*+ p *M($n "p) + t AgA; "flgL( p)] , (2) where 00 ~( * n ' p ) = 1 -gn-" 2 (2n-exp [ -(2n-~) " ( & n~p ) ] ,~ n = l 00 ~( p ) = 2 2 exp [ -(2n -I)"(&n"p)]," n = l p = A;"T,N 1 is the collection efficiency calculated with the full f~r r n u l a ,~ and N2 is the collection efficiency calculated with the thin-ring thin-gap approximation.6 The factor Nl /N2
Articles you may be interested inElectronically excited states in size selected solvated alkali metal atoms. II. Isotope effects in the spectroscopy of sodium water and sodium ammonia complexes Studies were made of the nitrogen-isotope effects occurring during the alkaline reduction of NOa-, N02-, and NH 2 0H with Fe(II). The pertinent reduction reactions were shown to be irreversible and the yields of NHa quantitative. The reduction of NOa-to NHa produced a k I4 /k 15 value of 1.075±O.OO4 at 25°C. A k 14 /k 15 ratio of 1.034±0.002 at 25°C was obtained for the reduction of N02-, or NH20H to NHa. The rate constant, kNOn was shown to be slow compared to k N02 -and k NH20 H which had values of 4.09X 1()-2 and 9.53X1o-a sec-I, respectively.The experimental data agreed well with results computed for a two-atom model in which the significant step in the reduction of each species was the breaking of an N-O bond. Reactions consistent with the experimental data were proposed to account for the reduction mechanism.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.