Kuvempu University 2009-1st Year B.Sc Chemistry - Question Paper
DSA-260
First Year B.Sc. Degree Examination Aug/Sept 2009 Directorate of Correspondence Course (Freshers)
PAPER - I: CHEMISTRY
Time : 3 Hours Max. Marks: 85
Note : 1) This paper consists of four sections. Answer all sections.
2) Write equations & neat diagrams wherever necessary.
I. Answer in a word, phrase or a sentence. 10x1=10
1. State Pauli's Exclusion principle.
2. How free radicals are formed?
3. Define Gold number.
4. What are propellants? Give one example.
5. Why sigma bond is stronger than pi bond?
6. What are isotonic solutions?
7. Define critical volume.
8. What are cycloalkanes?
9. What is Adsorption?
10. State Huckel's rule.
II. Answer any FIVE of the following. 5x3=15
11. Explain Berkeley and Hartley's method for determining the osmotic pressure of a dilute solution.
12. What is Hybridisation? Explain the formation of methane molecule on the basis of hybridisation.
13. a) Write a note on Wurtzs reaction. 2
b) Define most probable velocity. 1
14. Discuss the diagonal relationship between Lithium and Magnesium.
15. What is atomic hydrogen? How is it produced? Mention its uses.
16. The Vanderwaal's constants per mole of C02 are a=2.8 N M4 mol'2 & b=3.38x10-5M3 mol *. Calculate the values of critical temp & critical volume.
17. What are Emulsions? Mention types of emulsions with examples.
SECTION C
III. Answer any FIVE of the following. 5x6=30
18. a) Define ionisation energy. How does it vary along a period & down the
group? 3
b) Define covalent radius. How does it vary along a period & down a group? 3
19. a) State Markownikoffs rule. Give the reaction mechanism of addition of HBr
to propene. 3
b) Explain the acidic character of acetylene. 3
20. a) What are azeotropic mixtures? Give an example. 2
b) What is Ebullioscopic constant? 5 gm of a substance dissolved in 100 gm of water solvent produced a depression of 1.5c in the freezing point of the solvent. Calculate molecular weight of the substance Kf for water (1kg)=1.85. 4
21. a) How Nitrogen and Sulphur are detected by Lassaigne's test? Write
equations. 4
b) How do you synthesize cyclopropane by Freund's method? 2
22. a) Explain the mechanism of Friedel crafts alkylation of Benzene. 3 b) Give the mechanism of SN1 reaction. 3
23. a) Write the composition of Soda glass, potash glass & flint glass & mention
their uses. 3
b) Discuss the manufacture of cement by dry process. 3
24. Explain P-V Isotherms of C02 (Andrews curves), b) Explain the terms i) syneresis ii) Imbibition
SECTION - P
IV. Answer any THREE of the following. 3x10=30
25. a) Give any three applications of colloids. 3
b) Draw the shapes of d orbitals. 3
c) Give the mechanism of chtorination of methane. 4
26. a) Define RMS velocity. Calculate RMS velocity of C02 at 27c. 3
b) What are i) Electrophiles ii) Nucleophiles iii) Carbanions ? 3
c) Derive the relation between molar-mass of a non-volatile solute & elevation in boiling point of solution. 4
27. a) What is magnetic quantum number? Give all the possible values of 'C &
'm* when n=3. 3
b) What are adsorption isotherms? Derive Langmuir adsorption isotherm equation for unimolecuiar layer. 4
c) Explain the classification of elements in the periodic table on the basis of their electronic configuration. 3
28. a) State the distribution law. What are its applications? 3
b) Explain the laws of osmotic pressure. 3
c) Calculate the osmotic pressure of a 7% solution of cane sugar at 300K (Molecular mass=342, R=8.314 J/K/mol). 3
d) Define Inversion temperature. 1
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