Chemistry Laboratory XI

Synthesis and characterization of given organic compounds-

1.     To record the IR spectrum of the synthesized compound and interpret the vibrational frequencies

2.     To determine the absorption maxima of the synthesized compound spectrophotometrically in different solvents.

3.     To interpret the NMR spectra of the synthesized compounds

4.     To observe the mass spectral fragmentation pattern in the synthesized compound and predict the base peak and molecular ion peak.

One step synthesis (any two)

1.     Aldol condensation (Synthesis of dibenzal propanone)

2.     Acetylation (synthesis of acetanilide from aniline)

3.     Pechmann Condensation for Coumarin synthesis (Clay catalyzed solid state synthesis of 7- hydroxy -4-methyl coumarin)

Two step synthesis (any three)

1.     Benzoin → benzil → benzilic acid

2.     Benzophenone → benzopinacol → benzopinacolone

3.     Acetanilide → p-bromoacetanilide → p-bromoaniline

4.     Acetanilide → p-nitroacetanilide → p-nitroaniline

5.     Resorcinol → fluorescein → eosin

     Extraction of Organic Compounds from Natural Resources (any one)

1.     Isolation of caffeine from tea leaves.

2.     Isolation of casein from milk.

3.      Isolation of lactose from milk.

Scheme of Examination

The duration of examination will be 6 hrs.

The following exercises will be set in the examination

Organic Synthesis                                                          35 marks

Spectral Characterization                                                20 marks

Viva                                                                                15 marks

Total                                                                            70 marks

1.Organic synthesis

This exercise carries 20 marks. Synthesis will be allotted to the candidates by lot. The yield, purity, crystallization and recording of m.p. will be given due consideration while awarding marks. 

2.Spectral Characterization

This exercise carries 35 marks. The organic compound synthesised in the laboratory will be characterized on the basis of various spectroscopic techniques. The distribution of marks will be as follows.

·        Recording and interpretation of IR spectra                     7 marks

·        Determination of absorption maxima                              14 marks

·        Interpretation of the NMR and Mass spectrum                 14 marks

3.Viva

Oral questions shall generally be asked over the work assigned to the candidate. The purpose is to find out as to what extent the candidate has an understanding of the basic principles.