ias mains chemistry 2008
TRANSCRIPT
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' l l \ ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < ' < > < < 9 > ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ~ '
1 ... .. .I
ll \ .':';.. \: ;J W S . f l : ) ,
;;
Time Allowed: 3 hours Maximum Marks :
3
Can
li
dates should attempt Question Nos. I and 5 which are compulsory, and any three of the remaining
questions selecting at least one question from each Section. Assume suitable data
if
considered necessary
and mclicate the same clearly
PA,I R
' U
SEC11 NA
I
Answer any three of the
follo1Mng
(a) (i) State and explam Heisenberg's uncertamtypnnc1ple Why
1s ot
phcable to large
part1cles
b)
c)
d)
(10)
(ii) When
an
electron was accelerated through a ..E2
'
ference of I.
00
0.0 I
kilovolt, what is the uncertainty ofposition of 7 e ' c l o n g its line ofproj ection?
(I 0)
of a chem1cal bond?
ow does the pnnaple of 'max1mum o v e r l a
Enumerate the essential cond1tton
What
1s
atonuc rad1us of a
cub1c
Ia : atom1c packmg factor m s1mple
system, body- centered
cub1c
syste t e r e d
cub1c
system
(20)
cubic
2.
a)
3.
4.
b)
b)
(20)
What are semi conductors ? Explain n - type and p-typ semiconductors. Discuss the effect of
temperature on semiconductors.
i)
Derive the Kelvin equation for the vapour pressure of droplets and bubbles.
(ii) What are nucleation centres? Indicate their importance.
(20)
(I 0)
(I 0)
c) Explain the criteria of equilibrium and spontaneity in terms of U, S, A and G.
(a) i)
(20)
The third law of thermodynamics states an impossibility. Justify this statement.
(I 0)
................................................................................................................................................................................................................................................................................................................................................
. ~ 1
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5.
(ii) Explain why the molar entropy
of
ice crystals approaches 335 JIC
1
mor
1
, as the
temperature approaches zero kelvin.
(I 0)
b) Define chemical potential. Explain its significance. Deduce equations for the variation of
chemical potential with temperature and pressure.
c)
i)
(u)
(20)
What is the maximum number of phases that can be in equilibrium at constant
pressure and temperature in two- and three- component systems?
For the reaction
N2
(g)+ JH2 g) ~
2NH3
g)
Kp = I
64
x
10'
at
670
K Calculate ll.G
0
(I 0)
(a) Define activity, activity coefficient and mean activity coefficient
of
u t t o n
Denve and use the Debye-Huckel hm1t1ng
law
for mean activity
and mdicate how
it can be extended to more concentrated solution. 0.
b)
c)
d)
(20)
Denve an equation
to
relate temperature on rate d cal cui ate the energy
of
activation
1)
"Tetrahedral complexes
of
3d t r a n
O : _ ~
always
of
high
spm
J u s t i f y ~ ~
statement
(I
0)
(u) Calculate the crystal field s
1h
nergy and spm-only magnetic moment of
[V(H20)6f
1)
(I 0)
formation than lanthanides " Just
fy
the
6.
a)
b)
7
b)
(10 10 = 20)
d explain the law of photochemical equivalence. How are the discrepancies of this
explained?
(20)
What are heterogeneous catalysts ? Discuss the characteristics and mechanism of reaction on
heterogeneous catalysts.
i)
(20)
Identify one significant role m biological processes for each of the following
elements:
Fe,
Mg,
K, Zn, I
(I 0)
(ii) How is iron stored and transported in mammals? What is the oxidation state of iron
for storage and transfer?
(I
0)
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(c) i)
(ii)
8 a) i)
b)
c)
The complex
[NiCI.t
is paramagnetic whereas [Ni CN).t
is
diamagnetic. Justify
the observations.
Explain the origin of pale pink colour of [Mn(H
2
0)
6
]
2
.
Explain the possible isomerism in the following complexes:
[Co(NH
3
)
5
Br]
SO
[Co(Nfu)sN02]
2
[Co(en)2Cl2]
(I 0)
(I 0)
(20)
(20)
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' i ' r ~ \ ; ~ . ~ . \ : ~ ~ \ ~ ~ ~ ~ ~ . ; ~ . \ ~ ; ~ . ~ : : ~ \ . ; : ~ ~ ~ : ~ . : \ ~ ~ ~ \ ~ ~ ; ~ ~ \ ~ ; ~ m ~
l - - - - - - - - - - - - - - - - - - - - - - - - - - - - ~ r . ;
{
Time Allowed: hours Maximum Marks : 3
a)
b)
c)
2
a)
b)
i)
>
ii)
i)
ii)
2
x I
0 = 20)
A ~
.:a
8llld E
_..D
e ~
Ozonolysis
of
C:... a
B c
C: O
Where B D are stronger electron donor than A and
E)
pro duces four ozonides. Explain
mechanistically.
Butadiene on reaction with Br-F mole
ratio=
I: I produces two products. Explain.
20)
I
0)
L
~
l
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3.
c) C
6
H
5
-Cl on reaction with NaOH in an autoclave produces phenol major), diphenyl ether and
p -phenyl phenol. Explain the mechanism of formation.
20)
d)
hy
p-nitro benzaldehyde does not follow benzoin condensation? Explain.
5)
e) C
6
H
5
CHO
is
refluxed
in
the presence of NaOH and excess HCHO. Write the major aromatic
product.
Identify the intermediates and pro ducts:
0
(a)
i)
C Hs -
CHO +
CH3C - CH3
base
Acid
CHz 0t)z
B
ltydrolylfis
) C
llaae
A
frl L
3--butadi.ene
excess)
+
e n z o q u i n o n e
(c) or,
A
heateri
Zn+-
atSO C
\rilhSe
5
add
AlCl,
--- --+A
Room temp.
5)
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4.
Identify the products in the following reactions:
:H,-CB,-C -Oi:t
(a)
C l
2
-t::lr_-1-0I't
(.,
bl
c)
CHO
CliO
.,..,,_..,
J : ~ l
CN"
to
0 .
,_;
u; l
i)
(ii)
\ t f \
< . : ~ t o i l ) , ~
< ; l i ~ J
. OCN,
(il
HCI
----->-A ;>lJ
(ii)
TINO,
r iC
Hj)
i:J.ojJo :od kl W i J ( C ~
ON
following in their electronic
2 x I 0
=
20)
Explain the appearance of m/z = 44 peak in the mass spectrum of CH
3
CH
2
CH
2
CHO.
i
The dehydration of I, 2-dimethyl cyclohexanol (cis or trans) gives three alkenes. How
i
can you distinguish them on the basis of their IR spectra?
2 x
I 0
=
2
0)
(d) (i)
The
geometric isomers of stilbene show at 278 and 294 nm. Assign each value to i
appropriate isomer and sketch them.
i
i
~ ~ ~ > ~ : - ~ ~ - ~ ~ - ~ ~ - ~ ~ - ~ ~ ~ - - ~ ~ - : - ~ - ~ - ~ ~ ~ ~ - ~ : : : . ~ - ~ ~ = ~ : ~ .
- ~ ~ - - - J l
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6.
7.
8.
h
H OH
2 x I 0= 20)
Identify A-D in the following
(a)
b)
c)
d)
(a)
b)
(c)
X 20)
(I 0)
(I 0)
How adipic acid can be produced from phenol (only
two
steps)? Q
2, 3-dimethyl-2-chlorobutane on E2 dehydrohalogenation gives ho y products? Can
they be distinguished by IR spectroscopy ? Justify your
+
Explain the mechanism o Hollowing transformation:
CJ
d i =0Y (j
..----
)
Whuhy
:sr.N NA
(ii) Mechanical.streng ylon is better than polyester. Explain.
(iii) Why o l l o w anti-Markovnikovs addition to
it
oscopy ? Give method for chemical separation of the
two
compounds.
(20)
(15)
(15)
(I
0)
(I 0)
(I 0)
(20)
w is azelaic acid obtained from oleic acid?
Azelaic acid HOOC(CH
2
)
1
COOH
Oleic
acid
CH
3
(CH
2
)
1
-CHCH(CH
2
)
1
COOH.
(I 0)
(c) A cyclonitrile can
be
polymerized
by
base catalyzed reaction but
not
by acid catalyzed
reaction. Explain.
d) In the mass spectrum of
CH
3
CH
2
C-OCH
3
the peaks
0