Tilka Manjhi Bhagalpur University 2007 B.Sc Chemistry PHYICAL - Question Paper

COPYRIGHT RESERVED AA (H - 1) –Ch (1 A) Phy

2008

Time : three hours

Full Marks : 50

Candidate are needed to provide their answers in
Their own words as far as possible.

The ques. are of equal value .
ans any 5 ques. in which
Q. No. one is compulsory.

1. Choose the accurate ans : 10
a. The compressibility factor of a van der waals gas at the critical points is :
A. Zero
B. 0.4
C. 0.5
D. 0.375
b. The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is :
A. Critical temperature
B. Boyl’s temperature
C. Invention temperature
D. Reduced temperature
c. Which reaction is pseudo – unimolecular ?
A. H2 + Cl2 -> 2HCl
B. Acid catalyzed hydrolysis of an ester
C. Base catalyzed hydrolysis of an ester
D. N2 O5 -> N2 O4 + ½ O2
d. The minimum energy needed for the reacting molecules to undergo reaction is :
A. Potential energy
B. Kinetic energy
C. Thermal energy
D. Activation energy
e. Which is not a characteristics of a catalyse ?
A. It modifications the equilibrium constant
B. It alters the reaction path
C. It increases the rate of reaction
D. It increases the avg. K. E. of the molecule
f. The position of Cl icon is NaCl structure are :
A. Corner of the cube
B. Center of faces of the cube
C. Edge centers of the cube
D. Corner as well as centers of the faces of the cube
g. The ratio ranging from the r. m.s. velocity of H2 at 50 K and that of O2 at 800 K is
A. 4
B. 2
C. 1
D. ¼
h. Colloids can be purified by :
A. Peptization
B. Coagulation
C. Dialysis
D. Bredig’s arc method
i. An aerosol is a colloidal system of :
A. A liquid dispersed in a solid
B. A liquid dispersed in a gas
C. A gas dispersed in a air
D. None
j. Which of the subsequent will have the highest coagulating power for as s colloid ?
A. PO43-
B. SO42-
C. Al3+
D. Na+
2. (a) Evaluate the integral sin x sec2 x dx. 3
(b) obtain the probability that a leap year opted at random will contain 53 Sunday? 4
(c) Write full form of the subsequent RAM , ROM and OCR. 3
3. (a) elaborate the assumption of Kinetic theory of gases ? Derive an expression for
Kinetic energy of a gas using Kinetic gas formula . 7
(b) compute the R. M. S. velocity of molecules of CO2 at 10000 C. 3
4. describe critical temperature , critical pressure and critical quantity . define the
relationship ranging from critical constant and van der Waals constant for gases . 10
5. Enumerate the different factors which influence the rate of areaction and explain the effect of temperature on such rates . show how the concept of activated complex , potential energy barrier and activation energy are introduced to discuss it. 10
6. (a) discuss the term order and molecularity of a chemical reaction . Derive expression for the rate constant of a 2nd order reaction when the initial concentrations are the identical . 7
(b) Initial concentration of 1st order reaction is 0.2 M and its specific rate constant is 0.08 sec-1 what is t1/2 of the reaction ? 3
7. (a) elaborate the characteristics of catalytic reaction ? 5
(b) define the adsorption theory of heterogeneous catalysis . 5
8. (a) explain legal regulations of relational indices ? 4
(b) What is meant by space lattice of a crystal ?Draw a unit cell for space lattices of
the subsequent kinds . 6
A. Simple cubic
B. Face centered cubic
C. Body centered cubic
10. (a) explain the origin of charge on colloidal particles . What is meant by electrical double layer and zeta potential ? 7
(b) What is meant by electrophoresis ? 3

Earning:   Approval pending.