IAS Mains Chemistry xx5

8/10/2019 IAS Mains Chemistry xx5

1/36

S l

.

No

26

4

CS

MA

IN

)EX

A

M,

20

10

C

DT

N

K

D

I

A

CH

E

M

IS

TR

Y

Paper 1

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specified

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the

dm ission

Certificate

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17/36

SI. No.

262

I C DTN K DIB

CHEMISTRY

Paper

II

l nm Allowed : Tflree Hours Maximum Marks : 300j

INSTRUCTIONS

Each question

is

printed both

in

Hindi and

in

English.

Answers must be written

in

the

medium

specified in the Admission Certificate issued

to

you, which must be s t a t ~ d clearly on the

cover

o f the Clnswer-book in the space

provided

for the purpose. Jlfo marks

will

be

.given for the answers

written in

a medium

other. than thai

specified

in the Admission

Certificate.

Candidates should attempt Question Nos.

and 5

whick

are compulsory,

and

any

thr

o f

the

remaining questions

selecting

at

least

Olle question

from

each Section.

Assume

suitable data

i f

considered necessary

and indicate

the

same clearly.

The number o f marks carried

by

each

question is indicated at the end o f the

question.

Symbols

and

notations carry

usual meaning,

unless

otherwise

indicated.

~ : ~ i

Cf T

~ 4


18/36

Section A

1 Answer

the

following : Ox6=60

t:

(a) Whether the following

compound

is aromatic,

non-aromatic or antiaromatic. Justify.

(b) In

the

reaction sequence

NHNH2

v .

+CH, C

2

H

5

) C O - -+ P )

BF,

(Q)

identify (P) and (Q) and -clearly show

isotopi-

cally labelled *N.

c)

Write the

major product X) o

the reaction

CH3(CHz)JCHCH3

CH30Na CzHsOH

(X)

I

F

.

(d) Write

the

major product

formed

on treatment

of

urea with

NaOBr.

Also write the

name of

the reaction

involved.

(e) Identify

intermediate

P) and product (Q) m

the

reaction

v

{P]

- Q]

C-DTN-K-DIB

2

(Contd.)


19/36

..........

u

en

1. HJ>1ktfud 'd'a1

Rt

R< d


20/36

f) A mixture

of

formaldehyde and p-methoxy

benzaldehyde

s treated with cone. KOH.

Write the products of reaction.

2.

a) Identify P) to S) in the

reaction

sequence

20

R)

KOH

ale.)

0

P)

H20

- - -- Q )

HCOOH

S}

H2/N i

2-3

atm

293

K

b) 2-Methyl-3-phenyl-2,3-butanediol

on

treatment

with H

S0

4

gives

a

major product X).

Identify

X) and write

a

mechanism to explain

its

formation.

Also

write

the

name

of reaction

involved. 20

c) Draw resonating

structures for

the

attack

of

S0

H+ at different

positions of Indole, ~ s i n

curved

arrows.

At

which position attack occurs

preferentially

? Draw

an energy profile

diagram

for the position of preferential attack.

20

C-DTN-K-DIB

4

Contd.)


21/36

~ )

' h R i ' l ' ' r n ~ ~ om p - . . r l < i l < f f i 1 6 l i 1 ~ & ~ : s 1 ~ t ~ ~

fil 'fOI

Cf>f

~ KOH ~ -d4 '11fll1.


22/36

3. a)

Answer

the following : 15

.

i)

A student carried out reaction of aniline

with concentrated

H N O ~ S

Write

the structure

of

product/s he is

likely

to

obtain.

ii) Write

a

mechanism

to

explain

the forma

. tion of

major

product in i).

iii)

I f the reaction in {i) is carried out

only

in

. nitric acid,

write

an equation for the

formation of No;.

b)

Identify P)

to R) in

the

following:-

15

P)

i) OCH3

ii)

H20 /H

OH

H C;Q

COCH3

Q)

c) Write

the

resonance

structures

following:

. + /C H = C 0

H c.

N ~

[ .

~ N O

R)

of the

15

Explain

its

aromaticity

in

nitration reaction.

C-DTN-K-DIB

6

Contd.)


23/36

-

' .

3 (ar) f . t A ~ M a ~ :att ~ (R) f q l q ~ " t A t : t : 15

(P)

-

(i) OCH

3

(ii) H20 /H

OH

c ~ .

anh.AICI

3

COCH

3

C-DTN-K-DIB

7

(Q)

R)

(Contd.)


24/36

C-DTN-K-DIB

Contd.)


25/36

ii)

iii)

HCI

peroxide

(

P)

CCI

4

CH

3

CH

=

CH2 ~ . .

peroxide

Q)

trans-2-butene

Br

2

[RJ-< S)

T)

4.

(ar)

H ' ' R l f t < ~ d

~ < f i r

fst;q,


26/36

Section B

5. Answer the

following

:

I0x6=60

(a)

Draw the

structure

present

in

DNA.

of

purine nucleotides

(b) Benzoic acid on reduction

with Na

in

liq

NH

3

gives 1,2-dihydroproduct, whereas, anisole

gives

2,5-dihydroproduct.

Explain.

(c) Predict

the

products and

explain the ir forma

tion

v

_c_H..:;3_c_o_c_H...:3; ..

A

v

(d)

What

chariges

do

you expect in the

electronic

spectrum of acetoacetic ester

in

hexane and

ether.

(e)

(f)

1

H

NMR

spectrum

recorded

for

CH

3

-CH=

CH

2

at

90

MHz

gave coupling constant (J) o f

5 Hz

for vinyl

protons.

If

spectrum

is

recorded

at

500 MHz,

write the expected value of co Jpiing

constant.

.

What

is the range of fingerprint region in infra

red spectrum.

Write the range in

which

.

.

carbonyl

group

normally absorbs.

C-DTN-K-DIB

10

(Contd.)


27/36

10x

6=6

0

m

1:1;

i

R ~

'"i

1"'

9f

\l'q

o1 1

1Ha

+w r

G ld

l'4l l

1

(

)

31


28/36

li. a)

i)

Define

thennoplast

and

Which are thennoplast

following?

PVC

Phenolics

Aminoresins

Polypropylene

Teflon

Nylan

PoIyster

Polystyrene

thermosets.

among the

Alkyd

resin

Polyethylene

ii) Differentiate between LDPE

and HDPE.

10+5=15

b)

Give the synthetic route of epoxy resin based

on

bisphenoi-A. Mention

the

principal fields of

applications of epoxy resins. 5

c)

Write the product formed in

quinoline

by

C r0

3

the oxidation of

10

d) Identify and B and discuss the

selectivity

of

the

reagents 2xl0=20

C-DTN-K-DIB

12

Contd.)


29/36

6. (ar) i ) ffl'f ~ ~ 4

t im. ffi ' f f i T ~

4 \ l N \ ~ 1

f . s 1 0 i 1 P I R < t ~

it i t

ffl 'f

~ l ~ < t ~ i t

?

. Rti 11 Pl'ffi .

Q;flt;;i'uM"'

q


30/36

7. a) Write the structures of possible

products

of

following

photochemical

reactions and

mention the

type

of

Norrish process

I or II) in

each.

15

i)

v

ii)

v

CH CH2

-

C .

CH2CH2CHCH

---

. I

. CH

3

b)

Photochemical 2 2)

addition

of

benzophe

none with cis-

and

t r a n s ~ 2 b u t e n e

yield

a

mixture of same products. Explain their

formation

with the

mechanism.

15

{c)

Which among

the following. A or

B)is

formed

when Pent-2-ene

is

oxidised by

s

4

and

NaHS0

3

? Explain its formation with the

mechanism. 10

CH

2

CH

3

I

CH2CH3

I

H C O I 1

H-C-OH

I

I

H --c -

OH

HO-C-H

I

I

CH

3

CH

A)

B)

C-DTN-K-DIB

14

Contd.)


31/36

7 .

(ar) f.h="'MMd Yii>l' lRetl H'f i ~ B > u m

i

( 'dit


32/36

d) Identify

the compound susceptible for

oxidation and justify

i)

CH3

I

CHNH,

l

CH,OH

i i )

e) Write the reagents required for the following

conversions. 10

i)

0

0

0

0

0

ii)

CH3

CHO

CH

1

CHO

C DTN K DIB

16

Contd.)


33/36

(G )

41P1Cfl


34/36

8. (a) An organic compound with molecular

formula

C

9

H

10

gives

following

spectral characteristics

(b)

c)

(d)

Electronic

: Amax

at 235

nm

spectrum

Infrared

spectrum

NMR

spectrum.

Mass

spectrum

3035;

3000,

2925, 1640, 990,

915, 740

and 615

cm-1

at 31(2H), 48(IH),

51(1H),

58(1H),

71(5H)

m/e

at 117

Suggest

possible

structure with

probable

justification for

each

spectral feature.

30

What characteristic bands.

will be observed in

the

r

spectrum of

J,phenylethanone?

10

Room temperature NMR spectrum of

acetylacetone

exhibits two close

by

peaks at

=

197

and 214 ppm. Explain the reason

for their origin. What

other

peaks will be

observed. 10

How would you determine molecular

wt of

acetone

on the

,basis

of

its

mass spectrum

?

Suggest possible fragmentation pattern.

10

C-DTN-K-DIB 18


35/36

s (ar) )

?

1 4 < . . ~ 6 ' 1 Slru'll'i


36/36

IC

DT

NK

DIB

I

T

d

i'i lt.. ' l

:

ifd

J f

f- [f

R

Documents

IAS Mains Chemistry xx5