12206 21314 3 Hours / 100 Marks

12206
21314
3 Hours / 100 Marks
Instructions –
Seat No.
(1) All Questions are Compulsory.
(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Use of Non-programmable Electronic Pocket
Calculator is permissible.
(7) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.
Marks
1.
a) Attempt any THREE of the following:
i)
Define system. Name the three types of system and
define each one of them.
ii)
Define elementary reaction and non-elementary reaction
with example.
iii)
Write steps for integral method of analysis of data.
iv)
Define space time and space velocity. Write its unit.
12
P.T.O.
12206
[2]
Marks
b) Attempt any ONE of the following:
2.
i)
Derive expression for entropy change of an ideal gas.
ii)
Define activation energy. What is its importance in
chemical reaction? How activation energy can be found
out graphically.
Attempt any TWO of the following:
a) Derive the temperature dependancy of rate constant from
collision theory.
b) The half life time for the conversion of ammonium cyanate
into urea at 303 k at initial concentration of ammonium
cyanate of 0.1 mole/l and 0.2 mole/l are 1152 minutes and
568 minutes respectively. What is the order of reaction and
find the value of rate constant.
c) We are planning to operate a batch reactor to convert A into R.
The stoichiometry is A ® R and rate of reaction is given in
the table. How long must we react each batch for the
concentration to drop from CAO = 1.3 mol/l to CA = 1.3 mol/l.
CA (mol/l)
– rA (mol/l.min)
0.1
0.1
0.2
0.3
0.3
0.5
0.4
0.6
0.5
0.5
0.6
0.25
0.7
0.1
0.8
0.06
1.3
0.05
2.0
0.045
06
16
12206
[3]
Marks
Attempt any FOUR of the following:
3.
16
a) Give the physical significance of Gibb’s free energy change.
b) Differentiate between order and molecularity of reaction
(four points)
c) Define half life. Write the equation for half life
(for n = 1 and n ¹ 1) and explain the terms.
d) What is hot spot formation in a fixed bed reactor? Give three
different methods by which it can be prevented.
e) Based on Van’t Hoff equation, explain why temperature
increase is not desirable for exothermic reaction.
f)
4.
The half life period of a reaction of 1st order is 240 sec.
Calculate the rate constant.
a) Attempt any THREE of the following:
i)
State first and second law of the modyna mils. Give
mathematical expression.
ii)
The pyrolysis of hydrocarbon is carried out with an
activation energy of about 80,000 cal. How much faster
is the reaction at 600°C than at 500°C.
iii)
Draw the graph of fractional conversion versus time for
iv)
1)
first order reaction
2)
second order reaction 2A ® products.
12
Describe with example the precipitation method of catalyst
preparation.
b) Attempt any ONE of the following:
06
i)
Define zero order reaction. Derive its mathematical
expression. Give the graphical representation also.
ii)
Derive the performance equation for constant volume
MFR in which irreversible first order reaction takes place.
P.T.O.
12206
[4]
Marks
Attempt any TWO of the following:
5.
16
a) Differentiate between fixed bed reactor and fluidized bed
reactor (eight points)
b) Explain types of catalyst poisoning with example (any four
types)
c) Derive the relation between Gibb’s free energy and equilibrium
constant.
Attempt any FOUR of the following:
6.
a) Explain any two types of intermediates formed in a
non elementary reaction.
b) Derive the relation for constant volume irreversible first order
reaction A ® B interms of concentration. Give the graphical
representation also.
c) Derive the relation between Kc and Kp.
d) How feed should be admitted when PFR’s are connected in
parallel?
e) Show graphically how to find conversion when MFR’s of
different sizes are connected in series.
f)
Why plug flow reactors are not put in series - Justify with
example.
16
12206
21314
3 Hours / 100 Marks