Master of Science II (Chemistry)Examination: Oct/Nov 2016
Semester IV (New CGPA)
SLR No. Day
Date Time Subject Name Paper
No. Seat No.
SLR SD
248
Saturday
19/11/2016
02.30 PM
to
05.00 PM
Chemical Kinetics
C
XIV
Instructions: Attempt in all five questions.
SectionIis compulsory.
Attempt any twoquestions from Section II and any two from
Section III
Answer to all questions (Section II and III) should be written
in the same answer book.
All questions carry equal marks.
Figures to the right indicate full marks.
Use of log table and calculators in allowed.
Total Marks:70
SECTION I
Q.1 Answer the following: 14
According to transition state theory write an equation for rate of a reaction for
a reaction between two molecules A and B.
Define collision number.
For a unimolecular reaction write a relationship between Ea and ΔH#.
According to collision theory what is orientation factor?
In a consecutive reaction the concentration reaches maximum
and decreases during the reaction.
Decomposition of a reactant A give simultaneously two products B and C
with rate constants k1 and k2. What would be the ration of products at the end
of the reaction?
Give an example of first order opposed first order reaction.
Explain Steady state approximation.
Define chain length.
Write the chain termination step in the reaction between H2 and Br2.
Define explosion limit of a chain reaction.
In general catalytic mechanism, write the condition for Arrhenius
intermediate.
Activation energy of a catalysed reaction is generally less than the
uncatalyzed reaction. (True or False).
What is an optimum pH in an enzyme catalysed reaction?
SECTION II
Q.2 Using vibrational partition functions of reactants A and B obtain an
expression for the rate constant.
07
Explain how the activation energy, enthalpy of activation and entropy of
activation of a reaction are calculated.
07
Q.3 Discuss in detail the kinetics of first-order opposed first opposed first-order
equilibrium reaction.
07
Obtain an expression for the maximum concentration of an intermediate is a
consecutive reaction.
07
Page 1 of 2
Q.4 Explain general aspects of chain reaction with a suitable example. 07
Define what is meant by a saddle point, reaction coordinate and explain the
tunnelling effect.
07
SECTION III
Q.5 In an acid catalysed reaction differentiate between protolytic and prototropic
mechanism.
05
Write a general mechanism of an enzyme catalysed reaction and obtain an
expression for Michaelis-Menten constant.
05
What are acidity functions? Explain their significance. 04
Q.6 Discuss weakness of the collision theory of reaction rates. 05
For a consecutive reaction
The values of k1 and k2 are 45 and 15 h-1 respectively calculate the time
required for the concentration of B to reach maximum.
05
What is an autocatalyzed reaction? Explain its kinetics with a suitable
example.
04
Q.7 Write a note on any three: 14
Reaction between polyatomic molecules.
Kinetics of second order opposed first order equilibrium reaction.
Thermal decomposition of acetaldehyde
Oscillatory reactions.