TITLE:
Using the Vapor Pressure of Pure Volatile Organic Compounds to Predict the Enthalpy of Vaporization and Computing the Entropy of Vaporization
AUTHORS:
Shawn M. Abernathy, Kelly R. Brown
KEYWORDS:
Vapor Pressure (VP), Enthalpy of Vaporization, Entropy of Vaporization, Volatile Organic Compounds (VOCs), Predict
JOURNAL NAME:
Open Access Library Journal,
Vol.2 No.9,
September
28,
2015
ABSTRACT: The objective of this investigation was to develop a vapor pressure (VP) acquisition system and methodology
for performing temperature-dependent VP
measurements and predicting the enthalpy of vaporization (ΔHvap) of volatile organic compounds, i.e. VOCs. High quality VP data were acquired for acetone, ethanol,
and toluene. VP data were also
obtained for water, which served as the system calibration standard. The
empirical VP data were in
excellent agreement with its reference data confirming the reliability/performance
of the system and methodology. The predicted values of ΔHvap for water (43.3 kJ/mol, 1.0%), acetone
(31.4 kJ/mol; 3.4%), ethanol (42.0 kJ/mol; 1.0%) and toluene (35.3 kJ/mol;
5.4%) were in excellent agreement with the literature. The computed values of ΔSvap for
water (116.0 J/mol·K), acetone (95.2 J/mol·K), ethanol (119.5 J/mol·K) and
toluene (92.0.J/mol·K) compared also favorably to the literature.