A Summary of Different Methods Used to Measure Vaporization Enthalpies BG Bourdon gauge C calorimetric determination GC gas chromatography GCC gas chromatography-calorimetry CGC correlation gas chromatography DM diaphram manometer DSC differential scanning calorimeter EB ebullometry GS gas saturation, transpiration
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A Summary of Different Methods Used to Measure Vaporization Enthalpies BG Bourdon gauge C calorimetric determination GCgas chromatography GCCgas chromatography-calorimetry.
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A Summary of Different Methods Used to Measure Vaporization Enthalpies
BG Bourdon gaugeC calorimetric determination GC gas chromatographyGCC gas chromatography-calorimetry CGC correlation gas chromatographyDM diaphram manometerDSC differential scanning calorimeterEB ebullometryGS gas saturation, transpirationHG Heise gauge
HSA head space analysisI isoteniscopeIPM inclined piston manometryME Mass effusion-Knudsen effusionMG McLeod gaugeMM mercury manometerOM oil manometerRG Rodebush gaugeSG spoon gaugeSTG strain gaugeT tensimeterTE torsion effusionUV ultraviolet absorption
A Summary of Different Methods Used to Measure Vaporization Enthalpies (continued)
TB thermobalanceTGA thermal gravimetric analysisTPTD temperature programmed thermal
desorption particle beam mass spectrometry
TRM thermoradiometric methodTSGC temperature scanning gas
ti = retention time of ith componenttnrr = retention time of a non retained reference
What does ta measure?
For a pure component, a plot of ln (vapor pressure) vs 1/T over a narrow temperature range results in a straight line. The slope of the line is equal to - g
lHm(Tm), the
enthalpy of vaporization.
A plot of ln (1/ ta) vs 1/T over a narrow temperature range results in a straight line. What does the slope measure?
Ruzicka, K.; Majer, V. “Simultaneous treatment of vapor pressures and related thermal data between the triple point and normal boiling temperatures for n-alkanes C5-C20,” J. Phys. Chem. Ref. Data 1994, 23, 1-39.