Diffusion Flashcards
(9 cards)
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
