An interpretation of the vapor phase second virial coefficient isotope effect: correlation of virial coefficient and vapor pressure isotope effects

W. Alexander Van Hook, Luis P. N. Rebelo, Max Wolfsberg

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

Experimental data on vapor phase second virial coefficient isotope effects (VCIEs) are reviewed and then interpreted using the general theory of isotope effects. Useful correlations are developed between -δ(ℬ - bo)/(ℬ - bo) = (-VCIE) and [ln(fc/fg)]*, where [ln(fc/fg)]* is the reference condensed phase reduced isotopic partition function ratio, and ℬ is the second virial coefficient, bo = 2πσ3/3, σ is the Lennard-Jones size parameter, and δ denotes an isotopic difference, light-heavy. [ln(fc/fg)]* can be straightforwardly obtained from measurements of vapor pressure isotope effects for TR = T/TCRITICAL < 0.7. We show (-VCIE) = ln(fp/fg2) where ln(fp/fg2) is the reduced isotopic partition function ratio associated with the equilibrium between isolated gas-phase monomer species and interacting pairs. At temperatures well removed from crossovers in ln(fp/fg2) or [ln(fc/fg)]*, ln(fp/fg2) = (0.4 ± 0.2) [in(fc/fg)]*.

Original languageEnglish
Pages (from-to)9284-9297
Number of pages14
JournalJournal of Physical Chemistry A
Volume105
Issue number40
DOIs
Publication statusPublished - 11 Oct 2001

Fingerprint

Dive into the research topics of 'An interpretation of the vapor phase second virial coefficient isotope effect: correlation of virial coefficient and vapor pressure isotope effects'. Together they form a unique fingerprint.

Cite this