Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

High pressure density and speed-of-sound measurements in n-undecane and evidence of the effects of near-field diffraction

Albo, P. A. G., Lago, S., Romeo, R., Lorefice, S.
J. Chem. Thermodyn. 2013, 58, 95-100
ABSTRACT
n-Undecane (C11H24) density and speed-of-sound measurements in liquid phase have been reported along five isotherms at temperatures between (278 and 318) K. The density results have been obtained at pressure up to 60 MPa by means of a vibrating tube DMA 512 while speed-of-sound measurements for pressures up to 100 MPa. The speed-of-sound values have been measured by means of a double-path pulse-echo technique at three different operating frequencies. It has been chosen to repeat the measurements at different frequency values because of the observed discrepancies in the fly-time determination. A particular emphasis has been done to analyze these discrepancies, not directly explicable by traditional diffraction corrections. Indeed we have deduced that the source of differences is ascribable to a combination of sample speed-of-sound, of the signal frequency and to the geometrical configuration of the experiment, that affect the determination of the fly-time of the ultrasonic burst.
Compounds
# Formula Name
1 C11H24 undecane
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Mass density, kg/m3 ; Liquid
  • Pressure, kPa; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Vibrating tube method
  • 20
  • POMD
  • 1
  • Speed of sound, m/s ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Pulse-echo method
  • 30