Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Winter 5th Sem New 2150503 Chemical Engineering Thermodynamics Ii Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? V (New) EXAMINATION ? WINTER 2019
Subject Code: 2150503 Date: 04/12/2019
Subject Name: Chemical Engineering Thermodynamics - II
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Define: (1) Partial molar property (2) Activity coefficient (3) Fugacity. 03
(b) Discuss the excess Gibbs free energy relation with activity coefficient
and chemical potential.
04
(c) Determine P-x-y data for chloroform (1) methanol (2) system at 35
0
C,
vapor pressure of chloroform and methanol is 39.54 KPa and 27.95 KPa
respectively. Margules parameters are: ?? 12
=0.738 and ?? 21
=1.868.
07
Q.2 (a) Define chemical potential and state its significance. 03
(b) Derive the expression to estimate fraction of initial mixture that is
vaporized at equilibrium using flash vaporization calculation.
04
(c) Derive Margules equations for determination of activity coefficients of a
binary system from the expression:
?? ?? ????
= (?? 21
?? 1
+ ?? 12
?? 2
)?? 1
?? 2
07
OR
(c) Show that for a binary system, Henry?s law is valid for component ?1?
then Lewis Randall rule is valid for component ?2?.
07
Q.3 (a) Write a short note on Bubble point equilibria. 03
(b) Write a short note on ?fugacity of a pure liquid?. 04
(c) A gas mixture of SO2(g) O2(g) and inert A(g) in mole ratio 1: 0.5: 2 enters
in a reactor at 30bar and 900K to produce SO3(g) as:
SO2(g) + 0.5 O2(g) ? SO3(g).Determine the degree of conversion at
equilibrium and composition of mixture leaving the reactor. Assume the
reaction mixture behaves like an ideal gas. K = 5.973 and K ?
= 1.
07
OR
Q.3 (a) Derive summability relation for partial molar properties. 03
(b)
Methanol (1)-acetone (2) system is described by the Van Laar activity
coefficient model. At 60
0
C the model parameters are ?? 12
= 0.47 and ?? 21
=0.78.
Estimate the activity coefficients for a solution containing 15mole% of
methanol.
04
(c) Derive equation for establish expression of standard Gibbs free energy
change of chemical reaction as a function of thermodynamic
equilibrium constant.
07
Q.4 (a) With neat diagram explain tangent-intercept method to estimate partial
molar volume of a binary solution.
03
(b) Discuss van Laar equations applicable in determination of activity co-
efficient for VLE at low pressure with suitable examples.
04
FirstRanker.com - FirstRanker's Choice
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? V (New) EXAMINATION ? WINTER 2019
Subject Code: 2150503 Date: 04/12/2019
Subject Name: Chemical Engineering Thermodynamics - II
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Define: (1) Partial molar property (2) Activity coefficient (3) Fugacity. 03
(b) Discuss the excess Gibbs free energy relation with activity coefficient
and chemical potential.
04
(c) Determine P-x-y data for chloroform (1) methanol (2) system at 35
0
C,
vapor pressure of chloroform and methanol is 39.54 KPa and 27.95 KPa
respectively. Margules parameters are: ?? 12
=0.738 and ?? 21
=1.868.
07
Q.2 (a) Define chemical potential and state its significance. 03
(b) Derive the expression to estimate fraction of initial mixture that is
vaporized at equilibrium using flash vaporization calculation.
04
(c) Derive Margules equations for determination of activity coefficients of a
binary system from the expression:
?? ?? ????
= (?? 21
?? 1
+ ?? 12
?? 2
)?? 1
?? 2
07
OR
(c) Show that for a binary system, Henry?s law is valid for component ?1?
then Lewis Randall rule is valid for component ?2?.
07
Q.3 (a) Write a short note on Bubble point equilibria. 03
(b) Write a short note on ?fugacity of a pure liquid?. 04
(c) A gas mixture of SO2(g) O2(g) and inert A(g) in mole ratio 1: 0.5: 2 enters
in a reactor at 30bar and 900K to produce SO3(g) as:
SO2(g) + 0.5 O2(g) ? SO3(g).Determine the degree of conversion at
equilibrium and composition of mixture leaving the reactor. Assume the
reaction mixture behaves like an ideal gas. K = 5.973 and K ?
= 1.
07
OR
Q.3 (a) Derive summability relation for partial molar properties. 03
(b)
Methanol (1)-acetone (2) system is described by the Van Laar activity
coefficient model. At 60
0
C the model parameters are ?? 12
= 0.47 and ?? 21
=0.78.
Estimate the activity coefficients for a solution containing 15mole% of
methanol.
04
(c) Derive equation for establish expression of standard Gibbs free energy
change of chemical reaction as a function of thermodynamic
equilibrium constant.
07
Q.4 (a) With neat diagram explain tangent-intercept method to estimate partial
molar volume of a binary solution.
03
(b) Discuss van Laar equations applicable in determination of activity co-
efficient for VLE at low pressure with suitable examples.
04
2
(c) For binary mixture of liquid A and liquid B, activity coefficients are given
by ln?1=0.6x2
2
and ln?2= 0.6 x1
2
. At T = 353K, vapor pressure of A, PA
sat
= 119.96KPa and that of B is PB
sat
=79.97KPa.Does an azeotrope exist at
353K? If so, determine the azeotropic pressure and composition.
07
OR
Q.4 (a) Derive an expression for partial molar volumes ?? ?
1
and ?? ?
2
using following
relationship for the molar volume of the binary liquid mixture of
components 1 and 2.
?? = ?? 1
?? 1
+ ?? 2
?? 2
+ ?? 1
?? 2
[B+C(?? 1
? ?? 2
)]
03
(b) Explain any two methods for estimation of fugacity of pure gas. 04
(c) A gas mixture containing 30 mol% of CO, 50 mol% of H2 and 20 mol%
of inert gas is to be used for synthesis of methanol as:
CO(g) + 2H2 (g) ?CH3OH (g)
Gases issued from the catalytic chambers are in chemical equilibrium
with respect to the reaction at 30 bar and 625K. Assume that the
equilibrium mixture forms an ideal solution, K = 5x10
-5
and K ? =1. What
is the percentage conversion of CO?
07
Q.5 (a) Explain criteria of stability for a single phase binary system. 03
(b) Draw neat diagram of idealized osmotic system and derive an equation
for osmotic pressure difference.
04
(c) Mixtures of n-Heptane (A) and n-Octane (B) are expected to behave as
an ideal solution .The total pressure over the system is 101.3 KPa. Use
vapour pressure data given below and construct
a) T- xA, yA diagram b) Equilibrium diagram for A.
T,K 371.4 378 383 388 393 398.6
PA
sat
, KPa 101.3 125.3 140 160 180 205.3
PB
sat
KPa 44.4 55.6 64.5 74.8 86.6 101.3
07
OR
Q.5 (a) For VLE with suitable example, draw diagram for minimum azeotrope. 03
(b) Determine the number of degree of freedom F for each of following:
(1) A system prepared by partial decomposition of CaCO3 into evacuated
space.
(2) A system of two miscible non reacting species which exists as an
azeotrope in VLE.
04
(c) With proper nomenclature draw three types of constant- pressure liquid-
liquid solubility diagram.
07
*************
FirstRanker.com - FirstRanker's Choice
This post was last modified on 20 February 2020