Physical Chemistry Third Edition

(C. Jardin) #1
484 10 Transport Processes

e.A smaller ion will always have a smaller effective
radius in aqueous solution.
f.If the elapsed time of a diffusion experiment is
quadrupled, the root-mean-square distance moved by
diffusing molecules is increased by a factor of two.
g.If a mixture of two proteins of equal density is
sedimenting in an ultracentrifuge, and if one protein
has twice the molar mass of the other protein, its
sedimentation velocity will be half as large as that of
the other protein.
h.The viscosity of a gas increases with increasing
temperature, whereas that of a liquid decreases with
increasing temperature.

10.64Show that if a metal bar with a uniform cross section is
in a steady state with different temperatures at the two


ends, the temperature must be a linear function of
position if the thermal conductivity does not depend on
temperature.

10.65A sleeve bearing has an area of 26.6 cm^2. It is lubricated
with an oil having a viscosity coefficient equal to
0.0237 kg m−^1 s−^1. If the film of oil has a thickness of
0.20 mm and the radius of the bearing is 2.00 cm, find the
frictional torque on the shaft if it is turning at 600
revolutions per minute. Assume that the oil does not slip
on the metal surfaces.

10.66The diffusion coefficient of 1,1,1-trichloroethane (TCE)
in carbon tetrachloride at 25◦C is equal to
1. 36 × 10 −^9 m^2 s−^1 and the viscosity of carbon
tetrachloride at 25◦C is equal to 9. 1 × 10 −^4 kg m−^1 s−^1.
Find the effective radius of TCE molecules.
Free download pdf