For ei gn- 1 2013
CHE MI STRY MARKI NG SCHE ME
FOREI GN- 2013
SET - 56/ 2/ 1
Q. no.
1
2
3
Ans wers
Met allic soli ds
Os moti c pressure
Zone refi ni ng
Mar ks
1
1
1
4
2-chl or o- 3- met hyl but ane
1
5
Phenol < 4-nitrophenol < 2, 4, 6-tri nitrophenol
1
6
CH3 - CH( OH)- CH2 - CHO
1
7
Because of +I effect or electron donati ng nat ure of met hyl group.
1
8
Hexa met hyl ene di a mi ne and adi pi c aci d
1
9
½
1
½
10
11
(1) Because of t he for mat i on of hydr ogen bond / due t o che mi cal i nt eracti on.
(2) Because on addi ng sodi u m chl ori de, vapour pressure decreases and i n or der t o freeze
t he sol uti on,t e mperat ure has t o be l owered.
1
½
a) k = 2. 303 l og [ A0 ]
t
[ A]
t = 2. 303
60 s- 1
1
l og 10
1
½
t=
12
13
0. 0383sec
a) Pepti zati on t akes pl ace.
b) Because of larger surface area.
Lyophili c sols
1. Lyophili c sols are sol vent attracti ng
1
1
Lyophobi c sols
1. Lyophobi c sols are solvent repelli ng
2. Reversi bl e
2.Irreversi
bl e
1
For ei gn- 1 2013
½+ ½
3. St abl e
3. Unst abl e
ex. Gu m, gel ati ne, st arch,rubber (any
one)
14
(any t wo)
ex. Met al sols, met al sul phi des (any one)
Al u mi na is leached out by usi ng conc. Na OH soluti on t o sodi um al umi nate and silica as
sodi um silicat e.
Al 2 O3 + 2Na OH + 3 H2 O
2Na[ Al ( OH) 4 ]
Al u mi ni um hydr oxi de or hydrat ed al umi na is t hen ppt. by passi ng CO2 gas wher eas
sodi um silicat e re mai ned i n sol uti on.
Al u mi ni um hydr oxi de is i gnit ed t o get pure al umi na.
(or expl ai ned i n any ot her correct suit abl e manner)
OR
(a)
Cu2 S+FeS
(b)
Depr essant is used t o separat e sul phi de ore sel ectivel y from a mi xt ure of two sul phi de
ores.
15
½+ ½
(i)
(ii)
HF < HCl < HBr < HI
NH3 < PH3 < As H3 < SbH3 < Bi H3
2
1
1
1
1
16
1
1
17
a) Hydr ogen bondi ng
b) Nucl eoti de i s sugar +nitrogenous base + phosphat e gr oup whereas Nucl eosi de i s sugar
+ nitrogenous base .
1+1
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For ei gn- 1 2013
18
19
1) Buna- S < Pol yt hene < nyl on- 6, 6
2) Neoprene < PVC < Nyl on- 6
1+1
d =z x M
a3 x NA
½
2. 7 g c m- 3 =
z=
z x 27 g mol - 1
( 4. 05 x 10 - 8 c m)3 x 6. 022 x 1023 mol - 1
2. 7 g c m- 3 x 6. 022 x 1023 mol - 1 x (4. 05 x 10 - 8 c m)
27 g mol - 1
z 4
He nce t he cubi c unit cell is f. c. c.
20
1
3
½
1
1) Ist order
2) – k
3) sec- 1
1x3=3
3
For ei gn- 1 2013
21
1 x3=3
22
22
i) Due t o discret e t etrahedral struct ure and angul ar strai n, whit e phosphor us is more
reacti ve whereas red phosphor us is pol ymeri c and t heref ore less reacti ve.
ii) Because of hi gher charge/si ze rati o of Sn4+.
iii) Due t o its ease of li berati ng nascent oxygen.
OR
(i) PCl 3
+3H2 O
(ii) XeF2 +PF5
(iii)2Na N3
23
i)
1x3=3
H3 PO3 + 3HCl
[ XeF] +[ PF6 ]2 Na + 3N2
1x3=3
Di br o mi dobi s-(et hane- 1,2- di a mi ne)cobalt(III) /
Di br o mi dobi s-(ethyl enedi a mi ne)cobalt(III)
ii)Ioni zati on isomeris m
iii) Because of back bondi ng(syner gi c bondi ng), CO st abilize t he co mpl ex mor e t han NH3.
4
1 x 3=3
For ei gn- 1 2013
24
i) Ret enti on of confi guration
ii)Inversi on of confi gurati on
iii) Race mi sati on
1x3=3
25
½
½
1
1
(b) Cr O3 / KMn O4 / Aci dified K2 Cr 2 O7
26
1x3=3
27
i) Hel pi ng , cari ng and setti ng an exa mpl e of true friendshi p.
ii) Tranquilizers
iii) Because i n excess it act as poi son and can harm t he ner vous syst e m.
1x3=3
28
(a) Kohlrausch’s l a w: stat es t hat li miti ng mol ar conducti vit y of an el ectrol yt e can be
represent ed as t he su m of t he i ndi vi dual contri buti ons of t he ani on and cati on of t he
1
el ectrol yt e.
It is used t o cal cul at e Λ0 m of even weak el ectrol yte ./ It is used t o cal cul at e degree of
di ssoci ati on.
5
1
For ei gn- 1 2013
(b)
28
R=ρ(l/ a)
Cell const ant l/ a=R /ρ=Rκ
=( 1500 Ω) x( 0. 15x10- 4 Sc m- 1)
=0. 225c m- 1
OR
o
o
o
E cell = E cat hode - E anode
1
1
1
½
½
= 0. 34 V – (-2. 36) V
= +2. 70V
o
2+
Ec ell = Ecell
o - 0. 059 l og [ Mg ]
+
2
[ Cu2 ]
1
Ec ell = 2. 70 V- 0. 059 l og ( 0. 001 M)
2
(0. 0001 M)
2. 70 V - 0. 059 l og ( 10 )
2
1
= 2. 70V – 0. 0295 V
=2. 6705 V
½
r G = - nFE
o
O
cell
1
½
= - 2 x 96500 C mol - 1 x 2. 70 V
= - 521. 1 kJ mol- 1
29
i) Because of t he absence of unpaired el ectron i n the for mati on of met allic bond / because
of non-i nvol vment of d- orbit al el ectrons i n t he formati on of met allic bond.
ii) Because of lant hanoi d contracti on.
iii) Because of i nco mpl ete filli ng of d-or bit als.
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For ei gn- 1 2013
i v) Because of l ow ∆hyd Ho and hi gh ∆a Ho of Cu2+ ion and Cu respecti vel y.
v) Because Cr 3+ has st able t 2g3 half filled confi gurati on.
29
2 Mn O2 + 4KOH + O2
OR
→2K2 Mn O4 + 2H2 O
Mn O4 2- under goes disproporti onati on reacti on i n aci d medi umt o gi ve MnO4 - i on.
3 Mn O4 2- + 4H+
→2 Mn O4 - +Mn O2 +2H2 O
i)
Mn O4 - + 8H+ + Fe2+
→Mn2 + + Fe3+ +4H2 O
ii)
2 Mn O4- + 16H+ + 5C2 O4 2- →2 Mn2 + + 10CO2 +8H2 O
30
1x5=5
1
1
1
1
1
a)
i) Because car bon of car bonyl gr oup i n et hanal is mor e el ectrophilic t han of ket one due t o
t he presence of one el ectron donati ng met hyl group.
ii) Because of t he absence of α- hydr ogen at om.
iii) Because of ext ensi ve associ ati on of hydr ogen bond / di merisati on i n carboxyli c aci d
b)
i) Add Na OH + I2, acet ophenone gi ves yell ow ppt. of CHI 3 whereas benzophenonedoes
not for m any ppt.
ii) Add Na OH + I2, et hanal gi ves yell ow ppt. of CHI 3 whereas benzal dehyde does not
for m any ppt.
(or any ot her correct suit able t est)
OR
7
1x3=3
1+1
For ei gn- 1 2013
30
1 x5=5
Sh. S. K. Munj al
Dr ( Mr s.) Sangeet a Bhatia
Pr of. R. D. Shukl a
Mr. K. M. Abdul Rahee m
Dr. K. N. Uppadhya
Mr. D. A Mi shra
Mr. Rakesh Dhawan
Mr. Deshbi r Si ngh
Ms. Neer u Sof at
Mr. Akhil eshwar Mi shr a
Mr. Vi r endr a Si ngh
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