Register Number
(Established under section 3 of UGC Act,1956)
Course & Branch : B.Tech - P-CHEM
Title of the Paper : Mass Transfer – II Max. Marks:80
Sub. Code : 619PT503SCHX1031 (2008-2009-2010) Time : 3 Hours
Date :17/11/2012 Session :AN
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PART - A (10 x 2 = 20)
Answer ALL the Questions
1. The relative volatility of a binary system is 4.13. Find out x – y data.
2. What is role of open system in distillation process?
3. Distinguish between packed and plate type of absorbers.
4.
What is meant by ‘HETP’? Give its mass transfer significance.
5. Define the ‘plait – point’ in liquid – liquid equilibrium diagram.
6. Write down the choice of solvents for liquid – liquid extraction operations.
7. Write down some of industrial adsorbents used in practically.
8.
What is the significance of ‘breakthrough curve’ in adsorption?
9. State few applications of gas separation membranes.
10. Define the terms: osmosis and reverse osmosis.
PART – B (5 x 12 = 60)
Answer ALL the Questions
11. A mixture containing benzene and toluene with 40% benzene and
60% toluene (by weight) is to be separated in a fractionating column to give product containing 96% benzene and bottom

product containing 95% toluene. Feed is a mixture of two-third vapour and one-third liquid. Find out the number of theoretical stages required if reflux ratio of 1.5 times the minimum is used.
Take relative volatility as 2.5.
(or)
12. Explain the procedure for construction for the stripping section of a distillation column using McCabe – Thiele method and also write down its assumptions made.
13. A packed tower is to designed to absorb SO
2
from air by scrubbing the gas with water. The entering gas is 20% by volume and the leaving gas is to contain 0.5% SO
2
by volume. The entering water is SO
2
free. The water flow is to be twice the minimum. The air flow rate is 975 kg/hm 2 . The temperature is
30

C and the total pressure is 2 atm, the equilibrium data is governed by y = 21.8x. Where y and x are in mole fraction units.
Compute the number of overall gas – phase transfer units.
(or)
14. Derive the relevant equations used for the determination of height of absorption column from basic principles.
15. Carbon disulphide (CS
2
) is used to extract iodine from its saturated aqueous solution. The distribution of iodine between carbon disulphide and water at equilibrium is given by
K

Y

X grams of grams of iodine / litre of iodine / litre of
CS
2 water
(a) Calculate the concentration of iodine in the aqueous phase if 1 litre of a saturated aqueous solution of CS
2
at 293 K containing
0.3 grams of iodine per litre of water stirred with 50 ml of CS
2
.
(b) Repeat the calculation for two ideal extractions using 25ml of solvent each time.
(or)

16. Explain the procedure for determining number of stages of counter – current extraction operations.
17. The equilibrium adsorption of acetone vapour on an activated carbon at 303 K is given by the following data: g adsorbed/g carbon
Partial pressure of acetone, mmHg
0 0.1 0.2 0.3 0.35
0 2 12 42 92
The vapour pressure of acetone at 303 K is 283 mm Hg. A litre flask contains air and acetone vapour at 1 atm and 303K, with a relative saturation of vapour pf 35%. After 2 g of fresh activated carbon has been introduced into the flask, the flask is sealed.
Calculate the final vapour concentration at 303 K and the final pressure neglecting the adsorption of air.
(or)
18. Discuss the following:
(a) Adsorption isotherms (b) Single stage adsorption.
19. Explain the following processes used for separation of liquid mixtures: (a) Dialysis and (b) Ion exchange.
(or)
20. Write detailed notes, with respect to the principle and application, on (a) Foam separation.
(b) Thermal and Sweep diffusion process.