cs mains 2010 CHEMISTRY Paper II
time Allowed Three Hours Maximu, Marks 300
.
INSTRUCTIONS
Each question is printed both in. Hi??di and in
English.
Answers· must be written in the mediu111
specifi.??d in 'the Adnzission Certificate issued
to you, which ,nust be statf!d clearly on the
cover of the 'answer-book in the space
provided for the purpose. No ,narks will be . . .,.
.given??for the a!'swers written in a n1ediu1n
. other than that specified in tlte Adniission
Certificate.
Candidates should atte,npt Question Nos. 1
and 5 which: are co,npulsoryt and any three
of the re,naining questions selecting at least
one question front. each Section.
Assiune suitable data if considered necessary
and indicate the same clearly.
The number of ,narks carried . by each
question is indicated at Ute end of the
question.
Synibols and notations carry usual ,neaning,
unless othenvise indicated.
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UPSC PORTAL
Section
1. Answer the fo11owing 1 Ox6=60
Whether the following co1npound is aromatic, non-aromatic or antiaromatic. Justify. <img src='./qimages/1015-1-a.jpg'>
In the reaction sequence <img src='./qimages/1015-1-b.jpg'> identify and and-clearly show isotopically labelled *N.
Write the major product of the reaction · <img src='./qimages/1015-1-d.jpg'>
Write the major product fom1ed on treatment of urea with Na0Br. Also write . the name of the reaction involved.
Identify intermediate and product 1n the reaction <img src='./qimages/1015-1-e.jpg'>
a mixture of formaldehyde and p-methoxy benzaldehyde is treated with conc.koh.write the products of reaction.
2. Identify to in the reaction sequence 20 <img src='./qimages/1015-2-a.jpg'>
2-Methy1-3-phenyl-2 3-butanediol on treatment with H 2 S04 gives a major product Identify and write a mechanism to. explain its · formation. Also write the name of reaction involved. 20
Draw resonating structures for the attack of S03H at different P.Osition?? of- Indole, ii.sing curved a??ows. At which position attack occurs preferentially? Draw an energy profile diagram for the position of preferential attack. 20
C-DTN-K-DIB 4 (Contd.)
3. Answer the following: 15
A student carried out reaction of aniline with concentrated HN03/h2S04• Write. the structure of product/s he is like]y to obtain. Write a mechanism to explain the formation of major product in
(iii). If the reaction in is carried out only in . nitric acid.; write an equation for the formation of NO2+.
Identify to in the following: • 15 .<img src='./qimages/1015-3-b.jpg'>
Write the resonance structures of the following:15 <img src='./qimages/1015-3-c.jpg'> Exp Iain its aromaticity in nitration reaction.
C-DTN-K-DIB 6 (Contd.)
Write the products of the reaction 15
src='./qimages/1015-3-d-1.jpg'>
src='./qimages/1015-3-d-2.jpg'>
(iii)<img src='./qimages/1015-3--d-3.jpg'>
4.(a)Sketch the mechanism of fol1owing reactions 5x3=45 <img src='./qimages/1015-4-a-1-2-3.jpg'>
draw the structures and annulenes and discuss their aromaticity. 15 section
5. Answer the following:
draw the structure of purine nucleotides present in DNA·
Benzoic acid on reduction with Na in liq NH3 gives 1,2-dihydroproduct, whereas, anisole gives 2,5-dihydroproduct. explain.·
predict the products and explain their formation <img src='./qimages/1015-5-c.jpg'>
What changes do you expect in · the electronic spectrum of acetoacetic ester in hexane and ether.
1 H NMR spectrum recorded for CH3-CH= CH2 at 90 MHz gave coupling constant of 5 Hz for vinyl protons. If spectrum is recorded at 500 MHz, write the expected value of coµpling constant.
What is the range of fingerprint region in in frared spectrum. write the range in which carbonyl group normally absorbs. C-DTN-K-DIB 1 0 (Contd.) Define thermoplast and Which are _thennoplast fo11owing
PVC
Phenolics Teflon Alkyd r??sin
Aminoresins Nylan polyethylene
Polypropy Jene Polyster
Polystyrene

Differentiate between· LOPE and HOPE. 1 5 Give the synthetic route of epoxy resin based on bisphenol-A .. ·Mention the principal fields of applications of epoxy resins. 15
Write product formed in the oxidation of . quinoline by Cr03-. 10
Identify A and B and discuss the selectivity of the reagents 2x10=20 <img src='./qimages/1015-6-d.jpg'>
7. · Write the structures? of possible products of following photochemical reactions and mention the type of Norrish process or II) in each. 15 <img src='./qimages/1015-7-a.jpg'>
Photochemical· addition of benzophenone with cis- and trans-2-butene yield a mixture of same products. Explain their formation with the mechanism. 15
Which among the following .(A or is formed when Pent-2-ene is" oxidised by Os0 4 and NaHS03 Explain its formation with the mechanism. 10 <img src='./qimages/1015-7-c.jpg'
7 Identify the compound susceptible for HI04 oxidation and justify 1 0 <img src='./qimages/1015-7-d.jpg' Write the reagents required for the following conversions. 1 0 <img src='./qimages/1015-7-e.jpg' C-DTN-K-DIB 1 6 (Contd.)
8. An organic compound with moJecul formula
C9H1 0 gives following spectral characteristics ..
Electronic A max at 23 5 nm
spectrum
Infrared · 3035?? 3000, 2925 1 640, 990,
spectrum 9 1 5 740 and 6 1 5 cm-1
NMR 8 at l 4·8( 1 S · l l
spectrum . 5 ·8( 1 7 · 1
Mass · m/e at · 117
spectrum
Suggest possible structure with probable
justification for each spectral feature. 30
(b)What characteristic bands. wil1 be observed in the ir spectrum of l -phenylethanone . 10
(c)Room temperature NMR · spectrum of acetylacetone exhibits· two clos?? by peaks at omega l·91 and 2· 1 4 ppm. Explain the reason for their origin . · What other peaks wiH be observed . 1 0 ·
(d)How would you determine molecular wt of acetone on the :basis _of its mass spectrum Suggest possible fragmentation pattern . 1 0
C-DTN-K-DIB 1 8 ..