Vapor pressure isotope effects in the benzene (B) --cyclohexane (C) system from 5 to 80 /sup 0/C. I. The pure liquids B-d/sub 0/,B-d/sub 1/,ortho-,meta-, and para-B-d/sub 2/, B-d/sub 6/,C-d/sub 0/, and C-d/sub 12/. II. Excess free energies and isotope effects on excess free energies in the solutions B-h/sub 6//B-d/sub 6/, C-h/sub 12//C-d/sub 12/, B-h/sub 6//C-h/sub 12/, B-d/sub 6//C-h/sub 12/, and B-h/sub 6//C-d/sub 12/

Journal Article · Sat Apr 01 04:00:00 EST 1978 · J. Chem. Phys.; (United States)

OSTI ID:5120323

Jakli, G; Tzias, P; Van Hook, W A

High precision measurements of the vapor pressure differences between some deuterated benzenes B-d/sub x/ (x=1, para-2, and 6) and protio benzene B-d/sub 0/; between para- and ortho-, and para- and meta-dideuterobenzene; and between perdeuterocyclohexane C-d/sub 12/ and protiocyclohexane C-d/sub 0/ were made from near the freezing point to the normal boiling point. The data are best represented as the logarithmic ratios ln R (d/sub 6/) =ln (P/sub d/0/P/sub d/6) =1226.5/T/sup 2/-12.178/T, ln R (para/ortho) =ln (P/sub parahyphend/2/P/sub orthohyphend/2) =2.6/T/sup 2/, and ln R (para/meta) =ln (P/sub parahyphend/2/P/sub metahyphend/2) =-2.0/T/sup 2/, together with the deviations from the law of the mean ..delta.. (d1) =6-(ln R (d/sub 6/)/lnR (d/sub 1/))=0.177-3.6 x 10/sup -4/t and ..delta.. (d/sub 2hyphenpara/=3-(ln R (d/sub 6/)/ln R (d/sub 2hyphenpara/))=0.028 +1.0 x 10/sup -4/t. The isotope effects are inverse and display significant deviations from the law of the mean. The cyclohexane results are given by ln R (C-d/sub 12/) =-2188.4/T/sup 2/-18.587/T. New measurements of the vapor pressures of benzene--cyclohexane solutions are also reported between 5 and 80 /sup 0/C. The data are in good agreement with the best earlier work. Excess free energies of the equimolar solutions B-h/sub 6//B-d/sub 6/ and C-h/sub 12//C-d/sub 12/ have been measured between 20 and 80 /sup 0/C. Suitable fits to the data yield the following results (30 /sup 0/C); G/sup ex/(B-h/B-d), G/sup ex/(C-h/C-d); H/sup ex/(B-h/B-d),

• Research Organization: Chemistry Department, University of Tennessee, Knoxville, Tennessee 37916
• OSTI ID: 5120323
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 68:7; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
ALKANES
AROMATICS
BENZENE
CYCLOALKANES
CYCLOHEXANE
DEUTERIUM
DEUTERIUM COMPOUNDS
DISPERSIONS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MIXTURES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
SOLUTIONS
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
VAPOR PRESSURE