Vapor pressures of the isotopic waters and ices

Comments on H/D Isotope Effects on Polarizabilities of Small Molecules. Correlation with Virial Coefficient, Molar Volume, and Electronic Second Moment Isotope Effects

“…Equation (22) is first order in isotopic difference, so terms involving "a" cancel. The least squares derived value of "Aa" is equivalent to Av* = (0.8±0.1) cm -1 C -1 and corre lates nicely with value of 1.4 cm -1 C _1 cited above [27]. O n the other hand we have not attem pted a rationalization at the molecular level for the large inverse IE on d2 00 .…”

“…F o r example at 313.15 K the total ZP E shift on condensation for the two OH stretching frequencies is about 330 cm -1 to the red, but that phase frequency shift depends on tem perature (be cause of the tem perature dependence of the extent of hydrogen bonding). Van Hook [27] has demonstrated consistency between spectroscopic [28] and vapor pressure isotope effect (VPIE) measurements using tem perature dependent O H stretching frequencies, A(SvOH)/5T = 1.4 cm -1 C -1 . To introduce tempera ture dependence into the present formalism and arrive at (22), we recognized that to reasonable approxi m ation one can replace Av* by Av* (1 + Aa t) and v* by v * ( l+ a t) and assume Aa<^a.…”

Isotope Fractionation of Water during Evaporation without Condensation

“…Indeed, R evap was observed to evolve toward equilibrium fractionation as r jet was increased from <3 to 15 [27][28][29][30] Equilibrium isotope fractionation is a well-characterized phenomenon that describes the generally larger vapor pressure of an isotopically light species compared to that of the heavy isotopomer relative to the corresponding condensed phase composition. 31,32 The value of R eqm for pure water shows no significant dependence on isotope composition. [27][28][29][30] Fractionation arises from the different water isotopomers having different zero point energies for their vibrational, librational, and hindered translational motions.…”

The Dependence of the Oxygen Isotope Fractionation in the Hydration Water of CuSO4 · 5 H2O on the Crystallization Temperature

“…According to Bigeleisen 13 and Van Hook 14 the formula derived for the temperature dependence in a restricted temperature range of the isotope fractionation in a system that includes gaseous and liquid phases, may also be applied to a system including liquid and solid phases. The parameters A and B for the four fractionation factors given in Table 4 have been determined by means of a least squares Fig.…”