CHEMICAL ENGINEERING - MASS
TRANSFER QUESTIONS AND VERIFIED
ANSWERS|100% CORRECT|GRADE A+
Flick's law of diffusion - ANSWER - states that the mass flux per unit area of a component is proportional
to its concentration gradient.
Steady state - ANSWER o System properties do not change with time.
o The energy being steadily transferred through the wall of a hot oven illustrates the example of steady-
state heat transfer.
Transient heat transfer - ANSWER o System properties do change with time.
o The rapid cooling of a cake that is at ambient temperature in a cooler.
Applications of mass transfer in pharmaceutical processes - ANSWER º distillation, drying, absorption,
liquid-liquid extraction, adsorption, membrane process etc.
What is mass transfer? and what does it involve? - ANSWER Net movement of mass from one location to
another location under the influence of concentration gradient.
º it involves mass diffusion occurring at a molecular scale and bulk transport of mass due to convection
flow.
Mode of mass transfer: Molecular Diffusion - ANSWER Molecular diffusion or molecular transport can be
defined as the transfer or movement of individual molecules through a fluid by mean of the random,
individual movements of the molecules.
What is the ideal gas law? - ANSWER is the equation of state of a hypothetical ideal gas.
What is mass diffusivity dependent on? - ANSWER It is dependent on temperature and concentration
and in thecase of gases it is substantially influenced by pressure.
TRANSFER QUESTIONS AND VERIFIED
ANSWERS|100% CORRECT|GRADE A+
Flick's law of diffusion - ANSWER - states that the mass flux per unit area of a component is proportional
to its concentration gradient.
Steady state - ANSWER o System properties do not change with time.
o The energy being steadily transferred through the wall of a hot oven illustrates the example of steady-
state heat transfer.
Transient heat transfer - ANSWER o System properties do change with time.
o The rapid cooling of a cake that is at ambient temperature in a cooler.
Applications of mass transfer in pharmaceutical processes - ANSWER º distillation, drying, absorption,
liquid-liquid extraction, adsorption, membrane process etc.
What is mass transfer? and what does it involve? - ANSWER Net movement of mass from one location to
another location under the influence of concentration gradient.
º it involves mass diffusion occurring at a molecular scale and bulk transport of mass due to convection
flow.
Mode of mass transfer: Molecular Diffusion - ANSWER Molecular diffusion or molecular transport can be
defined as the transfer or movement of individual molecules through a fluid by mean of the random,
individual movements of the molecules.
What is the ideal gas law? - ANSWER is the equation of state of a hypothetical ideal gas.
What is mass diffusivity dependent on? - ANSWER It is dependent on temperature and concentration
and in thecase of gases it is substantially influenced by pressure.
