Gujarat University 2005 B.Sc Chemistry -VIII - Question Paper

Seat No. : ____________
TB-02
Chemistry Paper-VIII
Time : three Hours] [Total Marks : 70
Instructions : (1) All ques. carry equal marks.
(2) Figures to the right indicate full marks to the sub ques..
I. (A) ans any 2 of the subsequent ques. : (8)
(1) explain the optical isomerism of spiran compounds.
(2) Indicate the products found by addition of bromine (Br2) to cis 2-butene and discuss its mechanism.
(3) discuss the chemical method to separate the racemic Lactic acid.
(4) discuss Cram’s rule with suitable illustration.
(B) ans the subsequent ques. : (6)
(1) explain the synthetic applications and mechanism of the subsequent reagent :
Aluminium isopropoxide
OR
Osmium tetroxide.
(2) explain the principle, mechanism and synthetic applications of the subsequent reaction :
Arndt-Eistert reaction
OR
Hoffmann reaction.
2. (A) ans any 2 of the subsequent ques. : (7)
(1) explain the effect of leaving group on the reactivity of nucleophilic substitution reaction.
(2) Write a note on ‘Neighbouring group participation’.
(3) explain the stereochemistry of SN1 and SN2 reactions.
(4) Write a note on ‘Neopentyl effect’.
(B) ans any 2 of the subsequent ques. : (7)
(1) provide evidence to prove Benzyne mechanism in nucleophilic aromatic substitution reaction.
TB-02 three P.T.O.
(2) Both m-bromo anisole and o-bromo anisole provide only 1 product with sodamide in presence of liquid ammonia. – discuss.
(3) 2, 4–dinitro chlorobenzene with aqueous Na2CO3 at 130°C provide 2, 4–dinitro phenol – discuss.
3. (A) ans any 2 of the subsequent ques. : (8)
(1) Prove that Citral is an a-ß-unsaturated aldehyde compound.
(2) Prove the position of double bond and hydroxyl group (–OH) in a–Terpineol.
(3) provide synthesis of Camphor from Camphoric acid.
(4) Prove the presence of 2 ß–ionone units in ß-carotene.
(B) ans any 2 of the subsequent ques. : (6)
(1) Prove that Coniine is a–propyl piperidine compound.
(2) provide evidence for the attachment position ranging from pyridine and pyrrolidine rings in Nicotine.
(3) provide synthesis of Tropic acid.
4. (A) ans any 2 of the subsequent ques. : (10)
(1) Prove that both the monosaccharide units current in (+) Lactose have pyranose ring and connected by C1–C4 linkage.
(2) provide reactions which prove the structure of Sucrose.
(3) Prove the structure of Amylopectin.
(B) provide synthesis (any two) : (4)
(i) Guanine (ii) Uracil (iii) Thymine
5. (A) ans any 2 of the subsequent ques. : (5)
(1) discuss the classification of Drugs.
(2) provide synthesis of : Benzocaine.
(3) provide synthesis of : Trimethoprim.
(B) ans any 2 of the subsequent ques. : (5)
(1) Write a note on ‘Vat dyes’
(2) provide synthesis of : Eosin
(3) provide synthesis of : Alizarin.
(C) ans any 2 of the subsequent ques. : (4)
(1) elaborate pesticides ? provide their classification.
(2) provide synthesis of : DDT
(3) provide synthesis of : Aldrin.
_________
TB-02 4

Earning:   Approval pending.