Download SGBAU (Sant Gadge Baba Amravati university) B-Tech/BE (Bachelor of Technology) 4th Sem Chemical Engineering Chemical Engineering Thermodynamics II Previous Question Paper
Time : Three Hours lmml?mj?jl l" Max. Marks :
B.Tech. Founh Semester (Chemical Engineering) (CGS)
10992 : Chemical Engineering Thermodynamics-II : 4 CH 02
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Notes :
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Answer three question from Section A and three question from Section B.
Due credit will be given to neatness and adequate dimensions.
Assume suitable data wherever necessary.
Diagrams and chemical equations should be given wherever necessary.
Illustrate your answer necessary with the help of neat sketches.
Discuss the reaction, mechanism wherever necessary.
Mobile phones are strictly prohibited.
Use of pen Blue/Black ink/re?ll only for writing the answer book.
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SECTION ? A
An ideal gas(1mole) is allowed to expand in a single step from an initial pressure of 10
atm and at 300 to a ?nal state of 1 atm and 300K. The gas is compressed in a single step
to bring it to the initial state. Calculate Wexp and mep & interpret the result.
De?ne coef?cient of thermal expansion (a) & compressibility ([5). Derive the relation betn
the (x & B.
OR
An ideal gas (Cpm = 29.1Jk?lmol'l) is expanded reversibly and adiabatically from a
volume of 1.43dm3 at a pressure of 303975 Pa and temp. 298K, until the volume is
mm?cmmw
i) The ?nal temp & pressure of the gas
ii) q, w, AE &AH for the process.
Prove that Isothermal reversible work of expansion is always greater in magnitude than
that of irreversible expansion of on ideal gas.
Derive the expression for Gibbs-Duhem Margules equation and explain its application in
detail.
0R
100g of ethanol & methanol are mixed at 20?C to prepare an ideal mixture the vapour
pressure of the pure methanol is 88.7mm and that of ethanol is 44.5mm at 20?C. Calculate
i) The vapour pressure of solution
ii) The partial vapour pressure of ethanol & methanol in solution
iii) The vapour phase composition.
Calculate the enthalpy, entmpy and free-energy of mixing of one mole toluene and two
moles of benzene at 25?C.
14
C)
5. a)
b)
6. a)
b)
7. a)
b)
8. a)
b)
9. a)
b)
10. a)
b)
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Calculate the fugacity of ammonia at 502nm and 298K, given that the gas obeys the
equation of state PW," ? h) = m . and b = 0.037 dm?mor' .
wa g of cytochrome (M 2 =12400) is dissolved in 100g of water at 25?C. Calculate the
freezing point depression, boiling point elevation, lowering of vapour pressure and
osmotic pressure ol?the solution at 25?C. (Kf = 1.86, Kb = 0.52, vapour pressure of water
at 25?C = 24mm Hg)
Calculate the osmotic pressure of an aqueous solution containg 2g of protein
(M2 = 69000 gmor' ) per 100ml at 27?C
i) in centimeters ot'mercury
ii) in centimeters ot?watcr
(Take density ofsnlution 1g cm3 and 1 atm = 1013250 dync cm?z)
()R
Prove that the F rec7ing point depression is an colligative properties.
Calculate the mass ot?mcthyl alcohol which when dissolved in 100g of water, would just
prevent the fomlationofice at 40?C. tkfot'wateris 1.86Km01a1'1)
SECTION - B
State the Gibbs?phase rule and explain the meaning of the terms and symbol used.
Derive the conditions of thermal, mechanical and chemical cquilibria for a two-phase
system.
()R
Construct a phase diagram for water showing the three phases.
Explain in detail the term critical solution temperature (CST) & state the effect of
impurity of C ST.
De?ne the temu statical thermodynamic & explain the quantum mechanical aspect of
thermodynamics in detail.
What is the probability that 2 moles of water originally at 50?C will spontaneously separate
into 1 mole water at 49?C & 1 mole water at 51?C (Cpm = 751 k"mor?) .
OR
Explain and illustrate the following terms:
1) Assembly ii) Ensemble
iii) Con?guration iv) Probability
De?ne thermodynamic probability & derive the expression for thermodynamic probability.
I?J
ll.
12.
b)
b)
10 molecules of a gas are present in a container maintained at 298K. What is the probability
that all ten molecules will be found simultaneously in one half of the container?
Derive the expression for chemical af?nity (Af) and explain how it is useful to decide the
feasibility of the chemical reaction.
The equilibrium constant for the reaction A =M is 0.10 at 300K calculate
a) AG and
b) AG? for the production of lmole of M at a pressure of 1 atm from A at a pressure of
20 atm.
c) Predict the nature of the reaction under the latter conditions.
0R
For the reaction represented by 802(g) + H2 02(g) ->SO3(g). kp =1.7x1012 at 300K.
Calculate kp for the following reactions at 300K.
i) 303(8) ?* 302(g)+H202(g)
ii) 2803(g) -> 2 502(3) + 02 (3)
iii) 2502(g) + 02(g) ?> 2803(g)
3.176 g of N204 when take in a I lit vessel at 25?C gives a total pressure of 760 ton on
dissociation. Calculate the degree of dissociation a , and equilibrium constant kp. What
would be the value of a , if the total pressure is only 0.Satm?
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This post was last modified on 10 February 2020