Reference no: EM132329968

Advanced Mass Transfer -

Question No. 1 is compulsory. Answer any Five questions from the rest. All questions carry equal marks.

Q1) Write very briefly about the following:

a) Fick's second law and its application

b) Different Mass transfer coefficients

c) Raoult's law and Henry's law and their applications

d) Give the j_D correlation for mass transfer in flow parallel to flat plate

e) Chilton - Colburn analogy

f) Capacity coefficients and their use

g) Marangony effect

Q2) Explain and derive the Mass transfer flux equation for molecular diffusion in gases for the case of (i) Equimolar counter diffusion and (ii) A is diffusing through stagnant non diffusing B.

Q3) a) Explain the diffusion through a varying cross sectional area and derive the equation for mass transfer flux.

b) A sphere of naphthalene having a radius of 2.00 mm is suspended in a large volume of still air at 318 K and 1.01325 x 10⁵ Pa. The surface temperature of the naphthalene can be assumed to be at 318 K and its vapor pressure at that temperature is 0.555 mm Hg. The D_AB of naphthalene in air at 318 K is 6.92 x 10^-6 m²/s. Calculate the rate of evaporation of naphthalene from the surface.

Q4) a) Explain briefly about the diffusivities in gases.

b) Explain briefly about the diffusivities in liquids.

Q5) Explain the diffusivities of electrolytes in liquids

b) Predict the diffusion coefficients of dilute electrolytes for the following cases:

i) For KCl at 25^oC, calculate D⁰_AB.

ii) For KCl at 18.5^oC, calculate D⁰_AB.

iii) For CaCl₂ at 25^oC, calculate D⁰_AB. Also predict Di of ion Ca⁺² and of Cl^-.

Data: λ₊(K⁺) = 73.5, λ_-(Cl^-) =76.3, λ₊(Ca²⁺/2) = 59.5

Q6) Explain (a) The two film theory and (b) The penetration theory.

Q7) Explain the mass transfer in the laminar boundary layer when the fluid is in laminar flow over a flat plate.

Q8) Explain the following briefly.

a) Individual and overall mass transfer coefficients.

b) Reynolds analogy.

Note - Need elaboratively as per the questionnaire and also, need the reference book from which they have taken these and need the answers not from the web from the reference books with good clarification but with reference books names where applicable.