LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – CHEMISTRY
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THIRD SEMESTER – April 2009
CH 3502 – ORGANIC FUNCTIONAL GROUPS – I
Date & Time: 02/05/2009 / 9:00 – 12:00 Dept. No. Max. : 100 Marks
PART-A
Answer ALL questions. (10 x 2 = 20)
- What is Saytzeff rule? Give an example?
- What happens when n-propyl bromide is treated with alcoholic KOH?
- How will you distinguish between methyl alcohol and ethyl alcohol?
- Write any two drawbacks of Friedal-Crafts reaction with an example.
- How will you synthesise diethyl ether from ethyl alcohol?
- Give the general mechanism of nucleophilic addition reactions of carbonyl compounds.
- Write the mechanism of Cannizzaro reacton.
- Arrange the following compounds in order of increasing acidity and explain you answer.
HCOOH, ClCH2COOH, CH3COOH
- How will you synthesise succinic acid from ethylene?
PART-B
Answer ANY EIGHT questions. (8 x 5 = 40)
- a) What happens when propene treated with HBr in the presence of organic peroxides?
Explain.
- b) Discuss the mechanism of E2 reaction of alkyl halides.
- a) Why do aryl halides are less reactive towards nucleophilic displacement reactions?
- b) Write the general mechanism of aromatic electrophilic substitution reaction.
- How will you convert primary alcohol into tertiary alcohol? Explain.
- Discuss the mechanism of sulphonation reaction of phenol.
- Write a note on: Kolbe Reaction.
- Explain the mechanism of the reaction between aromatic aldehydes and aqueous alcoholic KCN.
- Write a note on: Norrish II reaction.
- How will you synthesis cinnamic acid from benzaldehyde? Give the mechanism.
- a) n-Butyl ether(bp 118 °C) has a much higher boiling point than its isomer diethylether (bp 35 °C).Explain.
- b) Write a note on: Cleavage of ethers by acids.
- Discuss the effect of the substituents on acidity of carboxylic acids.
- Write the mechanism of esterification reaction.
- How is adipic acid synthesized from cyclohexane?
PART-C
Answer ANY FOUR questions. (4 x 10 = 40)
- a) Write any five differences between SN1 and SN2 reaction mechanism. (5)
- b) Discuss the mechanism of E2 and explain any three evidences. (5)
- Complete the following reactions with mechanism. (5+5)
- a) Write the mechanism of wittig reaction. (5)
- b) Write a note on: Michael addition. (5)
- a) What is Williamson’s synthesis? (3)
- b) What happens when glycerol treated with KHSO4? (3)
- c) How will you convert acetaldehyde into paraldehyde? (2)
- d) Give the product when acetone undergoes the condensation in dry HCl. (2)
- Write the complete reaction for the following conversions. (4 x2.5)
- a) Ethylene bromide into succinic acid b) Butene into maleic acid
- c) Ethyl acetoacetate into crotonic acid d) Allyl alcohol into acrylic acid
- Predict the products of the following reactions. (5×2)