Answer a, b , c parts Transcribed Image Text: 13.
What are the three main mechanisms of
Diffusion in mass transfer processes?
Why is the effective diffusivity in porous solids
less than it would be in free liquid?
Give a simple laboratory experiment that could
be used to illustrate the following processes:
() Steady state molecular
(ii) Unsteady state molecular diffusion
Fick’s Law for mass transfer by molecular
diffusion can be expressed as
Define each of the terms in the above equation,
stating typical units, and explain the significance of
the negative sign.
How is Fick’s law modified to apply in the
() Eddy Diffusion
(ii) Diffusion through a porous solid