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FOURTH SEMESTER (CBCSS—UG) DEGREE EXAMINATION, APRIL 2022
Chemistry
CHE 4B 04—ORGANIC CHEMISTRY—I
(2019 Admission onwards)
Time : Two Hours Maximum : 60 Marks
Section A (Short Answers)

Answer at least eight questions.
Each question carries 3 marks.
All questions can be attended.

Overall Ceiling 24.

Distinguish between inductive effect and mesomeric effect.
Write a note on carbenes.

Which is the most acidic among chlorobutanoic acids ? Justify.

مم ‎DY‏ تن ا ‎re‏

Predict the product formed by the catalytic hydrogenation of propyne and reduction of propyne by
Lindlar’s catalyst.

=

Account for the acidity of terminal alkynes.
What is dipole induced dipole interactions ?
7. Explain the aromaticity in furan.

8. What is azulene ?

9. Why cyclopentadienyl anion is aromatic while the corresponding cation is not ?

10. The C - C bond length in benzene is 1. 39 A. Explain.
11. How is benzyne intermediate formed ?
12. How will you convert benzene to chloro benzene ?
(8 x 3 = 24 marks)
Section B (Paragraph)

Answer at least five questions.
Each question carries 5 marks.

All questions can be attended.
Overall Ceiling 25.

13. State Markovnikov’s rule. Explain its mechanism.

14. Write anoteon RS system of nomenclature for acyclic optical isomers with one asymmetric carbon
atom.
Turn over

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