Self‐Diffusion in Benzene‐Toluene and Benzene‐Cyclohexane Solutions

Abstract

The self‐diffusion in benzene‐toluene and benzene‐cyclohexane solutions have been measured at different temperatures. The capillary‐cell method was employed. The activation parameters of self‐diffusion for the systems are presented. The data have been used to test the validity of various diffusion equations proposed in the literature. The hypothesis that the self‐diffusion was realized by movement of aggregates of molecules is suggested.

A Kirkwood–Buff force field for the aromatic amino acids

“…104 Experimentally, D t,MOH decreases as x Ben increases from x Ben = 0.00 to x Ben ~ 0.50, and then the D t,MOH increases as x Ben approaches 1.0. 104 Our model for Ben + MOH does not capture the increase in D t,MOH at low x MOH , but the low simulated values seemed to agree with the presence of MOH-MOH clusters observed in our simulations and by others, 73–75, 105, 106 which one would expect to diminish the rate of diffusion of MOH. The experimental work referenced for the Ben + Tol system describes the diffusion in this system using a single linear fit in which the values of D t,Ben were assumed equal to the values of D t,Tol over the entire composition range.…”

Rate constants for the termination of benzyl radicals in solution

“…They agreed within 30% over the temperature range covered in this study and with another room-temperature value [20]. The data reported in [17] differ from those of [15,16,20] by nearly a factor of 2 for T 3 25°C and were not used. For cyclohexane solvent the diffusion coefficient was taken from D = [98 exp(1222/T)] X 10-5 cm2/sec extracted from the data of [l8,19], and for the mixed solvent the diffusion coefficients were taken from [19].…”

“…For the pure solvents the data are well described by Arrhenius laws with log A/(M-'-sec-l) = 11.9 f 0.1 and E, = (12.5 f 3.0) kJ/mol for toluene (-51OC I T I +58"C), and log A/(M-'-sec-') = 10.7 f 0.1 and E , = (8.1 f 2.0) kJ/mol for cyclohexane (l0OC I T I 59OC). The selfdiffusion coefficient of toluene has been measured by various groups [15-171 and activation energies of Efl = 10.5 kJ/mol [15], (13.0 f 0.4) kJ/mol [16], and (12.64 f 0.17) kJ/mol [17] have been reported. These values are very close to the activation energy of 2kt in toluene.…”

Acetonitrile-Water Solutions of Sodium Halides: Viscosity and Self-Diffusion of CH3CN and H2O

“…The viscosities of the solutions were determined using an Ubbelohde type viscosimeter with about 250 s outflow time of water. Water at 25 °C with density dw = 0.99708 g/cm3 and viscosity > ?w = 0.8903 mNs/m2 [23] was chosen as the reference liquid. The accuracy 0932-0784 / 88 / 0' 00-8 00 $ 01.30/0.…”