Abstract
The speed of sound in gaseous 1,1-dichloro-1-fluoroethane (CCl2FCH3, commonly known as R141b) has been measured between 260 and 315 K. Perfect-gas heat capacities and second acoustic virial coefficients have been calculated from the results. The second acoustic virial coefficients are used to estimate the density virial coefficients B(T) and an effective square-well potential. Our estimates of B(T) are consistent with B(T) deduced from high-quality p(Vm, T) results. We provided estimates of the vibrational relaxation time for R141b.