Diffusion Flashcards
The Fick’s Law of Diffusion gives the rate of diffusion based on
a. Pressure driving force
b. Temperature driving force
c. Concentration driving force
d. All of these
c
In steady state equimolar counterdiffusion, the following is true.
a. Nb=0; Na is constant
b. Na=0; Nb is non-zero ,
c. Na=-Nb; Na+Nb=0
d. NA+NB ,=constant
c
The enrichment of ethyl alcohol in the vapor phase from an aqueous ethyl alcohol solution during rectification is an example of:
a. Unicomponent diffusion
b. Equimolar counterdiffusion
c. Phase drift
d. Convective diffusion
b
rectification = equimolar
Ammonia (A) being absorbed from air (B) into water is an example of:
a. Steady state equimolar counterdiffusion
b. Steady state Unicomponent diffusion
c. Steady state multicomponent diffusion
d. Unsteady state equimolar counterdiffusion
b
pag may air = unicomponent
For a gas phase, Unicomponent diffusion through a gas-liquid interface will likely occur if:
a. One component is soluble and the other is not
b. Both components are soluble in the solvent
c. Both components are insoluble in the solvent
d. None of these
a
Molecular diffusivity of a liquid
a. Increases with temperature
b. May increase or decrease with temperature
c. Decreases with temperature
d. Is independent of temperature
a
total mass transferred to mass transferred by molecular diffusion
a. Schmidt Number
b. Sherwood Number
c. Reynolds Number
d. Nusselt Number
b
For turbulent mass transfer in pipes, the Sherwood Number depends on the Reynolds number (Re) as:
a. Re^0.33
b. Re^0.83
C. Re^0.53
d. Re
b
A dimensionless number that represents the ratio of the molecular momentum diffusivity to the molecular mass diffusivity.
a. Sherwood Number
b. Reynolds Number
c. Schmidt Number
d. Rayleigh Number
c
