Chemistry Pass 5th sem 2015 question paper. | Assam University.
CHEMISTRY
( Pass )
5th Semester
Course No. : CHMP-501
(-Inorganic, organic and Physical chemistry),
Full Marks : 35
Pass Marks : 12
Time: 2 hours
( Marks : 12 )
Answer four questions, taking one from each Unit
UNIT—I
1. Define hybridization. What angles are associated with the sp, sp3, dsp3 and d2sp3 hybridizations?
2. Between LICI and Lir, which has higher boiling point? Justify your answer with the help or Fajans’ rule.
UNIT—Il
4. (a) Between H and H ions, which one is more stable and why? 2
b) Write the molecular orbital electronic configuration of N2. 1
UNIT—Ill
5. Define hydrogen bond. Explain the type of hydrogen bond with suitable example. 1+2”3
6. (a) Calculate the number of atoms present per unit cell of f.c.c. lattice.
b) Predict the close packed structure of an ionic compound ABBe in which the radius of the cation is 148 pm and the radius of the anion is 195 pm, 1
UNIT—IV
7. Discuss briefly the theory and the chemical reaction involved in the estimation of Cu 24 ion by using standard sodium thiosulphate solution. 3
8. Describe the theory and principle in the estimation or Fe3 ion by using KMnO4. 3
GROUP—E3
(Organic Chemistry)
Marks : 11
Answer four questions, taking one from each unit
UNIT—V
9. Write the reagents used in the Meerwein-Pondort-Verley reduction an:l also write the utility of this reduction.
10. Describe briefly the Michael reaction. 2
UNIT—VI
11. (a) Explain why pyrrole, furan and thiophene are called superaromatic. 2
b) What happens when a mixture of furan, ammonia and steam passed over heated alumina?
12. (a) What happens when—
(i) pyrrole is treated with Zn in presence of acetic acid:
(ii) thiophene is reduced with H2 in presence of Raney Ni? 1+1-2n
(b) Write one method for the synthesis of thiophene.
UNIT—VI
13. Discuss briefly the Skraup quinoiine synthesis. 3
14. (a) Explain why pyridine preferabty undergoes electrophilic substitution at position. 2
(b) What happens when indole is treated with CHC13 and NaOH? 1
UNIT—VIII
15. (a) Write the possible electronic transitions shown by the following compounds 2
CH3-—NH, and ,-ci:
b) How will you distinguish the following two compounds with the help of
UV visible spectroscopy? 1
CH3—CH=CH—CH=CH----CH3 and CH2=CH—CH2---CH2----CH=CH2
16. With the help of IR spectroscopy, distinguish between the following :
(i) cH3—b—-CH3 and CH3—CHr-bHh on
(ii) CH3—Ce2-—CH2•--C-12—OH aad CH34_CHa (H3
GROUP—C
(-Physical Chemistry.)?
( Marks : 12 )
Answer four questions taking one from each Unit
UNIT--V
17. Describe briefly the variation or equivalent conductance or both the strong and weak electrolytes with dilution.
18. (a) state Kohlrausch’s law of independent migration of ions.
(b) The equivalent conductance at infinite dilution for BaNO3l2, H2S04 and HNO3 are respectively—
135O4x1O sn2equf1
4296Ox1Or4 S nr2equi:14
42124x1o-4 sm2equi
Calculate the equivalent conductance at infinite dilution for BaSO4. 2
UNIT—X
19. Define e.m.r. of a cell. Derive the relationship between the free energy change and the e.m.f. of a cell reaction. 1+2—3
20. (a) Write the expression for the Nernst equation at 2s C for a general cell reaction
ciA + 1,13 — cC + dD
also explain the terms involved in the
equation. 134L
Given
-1Y762 V and
E2÷1,=—(}126V?
Construct a cell by using these two electrodes. write the cell reaction and calculate the standard e.m!. or the cell. 1 /2
UNIT—Xl
21. (a) write the difference between thermal and photochemical processes. 2
(b) State Stark-Einstein law ot photochemical quivalence.
22. (a) Define quantuit yield. What should be the quantum yield ror primary processes in photochemical reaction? 1+11
(b) What is phosphorescence?
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