Thapar University 2006 M.C.A Organic Chemistry - Question Paper

Thapar Institute of Engineering & Technology
MCA (3rd Year)
Final Term exam
CB005 (Organic Chemistry)

i'ime: 3 Hrs    Max Marks: 72

THAPAR INSTITUTE OF ENGINEERING & TECHNOLOGY, PATIALA ORGANIC CHEMISTRY (CB-005)

End Semester Examination 14^th Dec., 2006

Note: Attempt any six questions in the given sequence.

All parts of a question must be attempted at one place.

Evaluated answer sheets can be seen on 18^th Dec., 2006 at 11.00 a.m. in Chemistry Lab

1.    (i) Describe rules for R,S system of nomenclature

(ii)    Discuss Meso compounds

(iii)    Describe separation of enantiomers    (4 x 3)

2.    Write short notes on:

(i) Terpenes    (ii) Steroids

(iii) Anomers of D-Glucose    (iv) Sucrose    (3 x 4)

3.    Discuss the following:

(i)    Chichibabin reaction

(ii)    Sodium borohydride reduction

(iii)    Wittig reaction

(iv)    Structure of furan    (3 x 4)

4.    (i) Explain important cleavages in the mass spectrum of 2-pentanone along with m/7, values.

(ii)    Discuss the effccts of solvent to aP-unsaturated carbonyl compounds in UV-Vis spectroscopy.

(iii)    What is the essential condition for a compound to be IR active? The IR

stretching frequency for O-H bond is_?_(higher/lower) than stretching

frequency of O-D bond. Explain.

(iv)    A signal has been reported to occur at 120 Hz downfleld from TMS in an NMR spectrometer with a 300-MHz operating frequency. What is its chemical shift? How many hertz downfield from TMS would the signal be in a 100-MHz spectrometer?

(3x4)

5. Give a structure(s) consistent with each of the following set of NMR data:

(i) C3H3CI5 a triplet, 5 4.52, 1H b doublet, 5 6.07, 2H (iii) CjHjBr a doublet, 8 1.04, 6H b multiplet. 5 1.95, IH c doublet, 8 3.33, 2H

(ii) C3H5CI3 a singlet, 8 2.20, 3H b singlet. 5 4.02, 2H (iv)CmHi>Cl a singlet. 8 1.57. 6H b singlet, 5 3.07, 2H c singlet, 8 7.27, 5H

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6.    (i) How does partition chromatography differ from adsorption chromatography?

(ii)    In a GC experiment in which the liquid stationary phase is polar, which would have a shorter retention time - a nonpolar mixture component with a high vapour pressure or a polar mixture component with a low vapour pressure? Explain.

(iii)    Which zones are heated in a GC instrument and why does each of these need to be heated?

(iv)    What is the difference between retention time and adjusted retention time?

(v)    What is gradient programmer?

(vi)    Distinguish between isocratic elution and gradient elution. ,    (2 x6)

7.    (i) Give two reasons why an injection system similar to that in GC would not work in HPLC.

(ii)    Distinguish normal-phase HPLC from reverse-phase HPLC.

(iii)    Will ethanol dissolved in CS2 or an undiluted sample of ethanol show an O-II stretch at a higher frequency in IR spectrum?

(iv)    Write the resonance contributions of pyrrole

(v)    What do you understand by enantiotopic hydrogens

(vi)    Calculate Xma_X for jt-mi* transition for the following in hexane (2x6)

Attachment: thapar-university-2006-m-c-a--26293-1.pdf

Earning:   Approval pending.