PTU Punjab Technical University B-Tech May 2019 Question Papers 4th Semester Petroleum Engineering
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(Petroleum Refinary Engineering) (2013 Batch) (Sem.?4)
CHEMICAL ENGINEERING THERMODYNAMICS
Subject Code : BTPC-404/BTCH-305
M.Code : 72427
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.
SECTION-A
1.
Answer briefly :
a) Find the density of nitrogen gas at NTP.
b) State 2nd law of thermodynamics.
c) What is throttling process? Give an example.
d) What is the significance of H-x diagram?
e) What do you understand by dew point and bubble point?
f) What is the physical significance of partial molar properties?
g) Define equilibrium constant. What is its significance?
h) What is the effect of pressure on equilibrium constant in a gas phase reaction?
i) Write two major applications of Gibb's Duhem equation.
j) What do you understand by theoretical flame temperature?
SECTION-B
2.
Calculate U and H in kJ for 1 kmol water, as it is vaporized at a constant temperature
of 373 K and constant pressure of 101.3 kPa. The specific volumes of liquid and vapour
at these conditions are 1.04 ? 10?3 and 1.675 m3/kmol respectively ; 1030 kJ of heat is
added to water for this change.
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3.
Write the Clapeyron equation and hence find the melting point of mercury at 10 bar,
where mercury has a density of 13.69 ? 103 kg/m3 in the liquid state and
14.193 ? 103 kg/m3 in the solid state, both measured at the melting point of 234.33 K and
1 bar. Heat of fusion of mercury is 9.7876 kJ/kg.
4.
Find the volume of n-pentane at 500 K and 20 bar following Van der waals equation of
state. Tc = 469.6 K, Pc = 33.7 bar
5.
State Hess's law of constant heat summation. Calculate heat of formation of the gaseous
ethyl alcohol at 298 K using following data :
Standard heat of formation of CO2 (g) = ?393.51 kJ/mol
Standard heat of formation of H2O (l) = ?285.83 kJ/mol
Heat of combustion of gaseous ethyl alcohol at 298 K = ?1410.09 kJ/mol
6.
Derive the expression for effect of temperature on fugacity coefficient.
SECTION-C
7.
Show that the fugacity of a gas obeying the van der waals equation of state is given by
b
2a
RT
In f
ln
, where a and b are van der Waals constants.
V b
RTV
V b
8.
Describe the criteria for chemical reaction equilibria. Calculate the equilibrium constant
for the reaction N2 + 3 H2 2 NH3 at 500 K assuming that the standard heat of reaction
is constant in temp. range 298 K to 500 K. Standard heat of formation and standard free
energy of formation of NH3 at 298 K are ? 46100 J/mol and ?16500 J/mol respectively.
9.
For a binary system of components (1) and (2), the vapour pressures are given by the
Antoine's equations
sat
2911.32
sat
2477.07
ln P
13.818
; ln P
13.859
1
T 40.00
2
T 56.56
P is in kPa and T in K. Assume the solution as ideal. Calculate :
a) The composition of liquid and vapour in equilibrium at 95 kPa and 335 K.
b) The composition of the vapour in equilibrium with a liquid containing 40% (mol)
pentane and the equilibrium temperature at P = 95 kPa.
c) The total pressure and the vapour composition in equilibrium with a liquid of
composition x1 = 0.40 at T = 333.2 K.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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This post was last modified on 04 November 2019