Please answer all the above questions correctly providing necessary formulae, equations, expressions, diagrams, charts, graphs, plots and tables.

a) On what factors, does the selectivity of a membrane depend? b) How can you distinguish between a homogeneous membrane and asymmetric membrane? Write the merits and demerits of both these types of membranes. c) How does the hydrophobicity/ hydrophillicity of a membrane affects its selection for use for a particular task. Explain with an example. d) What do you mean by molecular weight cut-off (MWCO) of a membrane? What is sharp cut-off or wide cut-off membrane? e) What are the basic transport mechanisms for solvent or solute flow through solid/liquid membranes? f) What are the main limitations of the membrane separation process? g) What is Darcy's law? Is it valid for solution? Explain. h) What do you mean by retention coefficient and reflection coefficient? Is there any relation between these two parameters? i) Why the sea water desalination process by membrane technology is known as "reverse osmosis"? Explain. j) What do you mean by concentration polarization in membrane process? Do you observe this phenomenon during electrodialysis? 102=20 2. (a) What are the parameters used for characterization of a membrane supposed to be used for pressure-driven applications, such as reverse osmosis, ultrafiltration, etc? (b) Write in details the methodologies used for determination of those membrane parameters based on experimental studies. Write all the steps clearly. Is it necessary to determine the membrane surface concentration in the process? Explain. 10+10=20