NOTES
1158
calculations for this system at the temperature region 280-360'. The fairly good agreement between the results obtained in our study and those from adsorption isostersl shows that the application of the transient response technique to reversible chemisorptions is worth studying, being a quick technique and pertinent to practical uses.
over the frequency range 60 kc-10 Mc using a Boonton Radio &-Meter (Type 260-A) and a General Radio Schering-type capacitance bridge (Type 716C). The comparison of both sets of data is shown in Table I.
Acknowledgment. The authors thank Dr. F. S. Stone of the Department of Physical Chemistry, The University of Bristol, for his interest in this work.
This work
Density, Viscosity, and Dielectric Constant of
Table I
Density, pZ50 d In v/dTb Viscosity log t) Dielectric constant, d In c/d In T
" Determined
c
Szwarc'
0.883 0.00133 3.670 395/T 1.50 2650/T -1.19
-
+ +
from -70 to 25".
*v
=
0,880" 0. 001085" - 3.655 393/T" - 1.495 2659/T" -1.16"
+ +
molar volume.
Tetrahydrofuran between -78 and 30°1
by Donald J. Metz and Althea Clines Brookhaven National Laboratory, U p t m , New York 11979 (Received November 1 , 1966)
Recently, Szwarc, et aLla published data on the density, viscosity, and dielectric constant of tetrahydrofuran between -70 and 25'. In an independent and simultaneous study, we determined these properties between -78 and 30". We would like to report that our data substantiate and confirm those previously published by both Szwarc2and We determined our densities pycnometrically, using dried and purified ethyl bromide as standard.6 Viscosity was measured in a modified Ubbelohde viscometer us. both ethyl bromide6 and diethyl ethere6 Dielectric constants were determined, us. ethyl bromide,"
T h Journal of Physical Chemistry
With the exception of the temperature dependence of density, the agreement between both sets of data is excellent. When the data of Kuss3 on the variation of density in the region of room temperature are included, there is a suggestion that the larger coefficient of expansion may be more nearly correct.
(1) This work was performed under the auspices of the U. 9. Atomic Energy Commission. (2) C. Carvajal, K. J. Tolle, J. Smid, and M. Szwarc, J . Am. Chem. Soc., 87, 5548 (1965). (3) E.Kuss, 2.Angew. Phys., 7, 376 (1955). (4) F. E.Critchfield, J. A. Gibson, Jr., and J. L. Hall, J. Am. Chem. Soc., 7 5 , 6044 (1953). (5) "International Critical Tables." (6) A. A. Maryott and E. R. Smith, National Bureau of Standards Circular 514,U.S. Government Printing Office, Washington, D. C., 1951.
