Related Experiment Video
Updated: Feb 19, 2026

A New Straightforward Method for Lipophilicity logP Measurement using 19F NMR Spectroscopy
Published on: January 30, 2019
Liquid-Phase Speed of Sound Measurements of Octafluorocyclobutane (RC-318) and Hexafluoroethane (R-116)
Aaron J Rowane1, Katrina N Avery1
1Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States.
None:
Sound speed data measured using a dual-path pulse-echo instrument are reported for octafluorocyclobutane (RC-318) at temperatures ranging from 240 to 390 K and at pressures up to 49.01 MPa, and for hexafluoroethane (R-116) at temperatures ranging from 230 to 320 K and at pressures up to 50.27 MPa. The combined expanded uncertainty in the speed of sound varies from 0.035% to 0.102% for RC-318 and 0.039% to 0.097% for R-116 of the measured speed of sound value. The data reported in the present study and those available in the literature are compared to reference equations of state (EOS) for RC-318 and R-116 included in REFPROP version 10.0. The overall performance of both EOS is characterized by an average absolute relative deviation and the maximum deviation. The RC-318 EOS compared to the reported sound speed data with an absolute average relative deviation of 0.56% and a maximum deviation of 1.62%. The R-116 EOS compared to the reported sound speed data with an absolute average relative deviation of 4.85% and a maximum deviation of 6.35%. In both cases, these comparisons show that a refitting of both EOS is required to accurately reproduce the liquid-phase speed of sound for RC-318 and R-116.
Related Concept Videos
Deriving the Speed of Sound in a Liquid
The speed of sound in fluids can be derived by considering a mechanical wave...
Speed of Sound in Gases
Speed of Sound in Solids and Liquids
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Mass Spectrometry: Cycloalkane Fragmentation
For example, cyclohexane molecular ions have a mass-to-charge ratio (m/z) of 84, which tends to produce a stronger signal than linear alkanes like hexane. This stability comes from...
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...

