CBSE Class 12 Chemistry Question Paper 2020 Set 56-3-1

H$moS> Z§.
Code No. 56/3/1
amob Z§. narjmWu H$moS >H$mo CÎma-nwpñVH$m Ho$ _wI-n¥ð
Roll No. >na Adí` {bIo§ &
Candidates must write the Code on the
title page of the answer-book.

ZmoQ> NOTE
(I) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _o§ _w{ÐV (I) Please check that this question
n¥ð> 19 h¢ & paper contains 19 printed pages.

(II) àíZ-nÌ _| Xm{hZo hmW H$s Amoa {XE JE H$moS (II) Code number given on the right
>Zå~a H$mo N>mÌ CÎma-nwpñVH$m Ho$ _wI-n¥ð> na hand side of the question paper
{bI| & should be written on the title page of
the answer-book by the candidate.
(III) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _| (III) Please check that this question
>37 àíZ h¢ & paper contains 37 questions.
(IV) H¥$n`m àíZ H$m CÎma {bIZm ewê$ H$aZo go (IV) Please write down the Serial
nhbo, CÎma-nwpñVH$m _| àíZ H$m H«$_m§H$ Number of the question in the
Adí` {bI| & answer-book before attempting it.
(V) Bg àíZ-nÌ H$mo n‹T>Zo Ho$ {bE 15 {_ZQ >H$m (V) 15 minute time has been allotted to
g_` {X`m J`m h¡ & àíZ-nÌ H$m {dVaU read this question paper. The
nydm©• _| 10.15 ~Oo {H$`m OmEJm & question paper will be distributed
10.15 ~Oo go 10.30 ~Oo VH$ N>mÌ Ho$db at 10.15 a.m. From 10.15 a.m. to
10.30 a.m., the students will
àíZ-nÌ H$mo n‹T>|Jo Am¡a Bg Ad{Y Ho$ Xm¡amZ read the question paper only and
do CÎma-nwpñVH$m na H$moB© CÎma Zht {bI|Jo & will not write any answer on the
answer-book during this period.

agm`Z {dkmZ (g¡ÕmpÝVH$)
CHEMISTRY (Theory)

{ZYm©[aV g_` : 3 KÊQ>o A{YH$V_ A§H$ : 70
Time allowed : 3 hours Maximum Marks : 70

.56/3/1 1 P.T.O.

gm_mÝ` {ZX}e :
{ZåZ{b{IV {ZX}em| H$mo ~hþV gmdYmZr go n{‹T>E Am¡a CZH$m g™Vr go nmbZ H$s{OE :
(i) `h àíZ-nÌ Mma IÊS>m| _| {d^m{OV {H$`m J`m h¡ – H$, I, J Ed§ K & Bg àíZ-nÌ _|
37 àíZ h¢ & g^r àíZ A{Zdm`© h¢ &
(ii) IÊS> H$ _| àíZ g§»`m 1 go 20 VH$ A{V bKw-CÎmar` àH$ma Ho$ àíZ h¢, àË`oH$ àíZ 1 A§H$ H$m
h¡ & àË`oH$ àíZ H$m CÎma EH$ eãX `m EH$ dmŠ` _| Xr{OE &
(iii) IÊS> I _| àíZ g§»`m 21 go 27 VH$ bKw-CÎmar` àH$ma Ho$ àíZ h¢, àË`oH$ àíZ 2 A§H$m| H$m
h¡ &
(iv) IÊS> J _| àíZ g§»`m 28 go 34 VH$ XrK©-CÎmar` àH$ma-I Ho$ àíZ h¢, àË`oH$ àíZ 3 A§H$m| H$m
h¡ &
(v) IÊS> K _| àíZ g§»`m 35 go 37 VH$ XrK©-CÎmar` àH$ma-II Ho$ àíZ h¢, àË`oH$ àíZ 5 A§H$m| H$m
h¡ &
(vi) àíZ-nÌ _| H$moB© g_J« {dH$ën Zht h¡ & VWm{n, Xmo-Xmo A§H$m| Ho$ Xmo àíZm| _|, VrZ-VrZ A§H$m| Hoo$
Xmo àíZm| _| VWm nm±M-nm±M A§H$m| Ho$ VrZm| àíZm| _| AmÝV[aH$ {dH$ën {X`m J`m h¡ & Eogo àíZm| _|
go Ho$db EH$ hr {dH$ën H$m CÎma Xr{OE &
(vii) BgHo$ A{V[aº$, Amdí`H$VmZwgma, àË`oH$ IÊS> Am¡a àíZ Ho$ gmW `Wmo{MV {ZX}e {XE JE h¢ &
(viii) Ho$ëHw$boQ>a AWdm bm°J Q>o~b Ho$ à`moJ H$s AZw_{V Zht h¡ &

IÊS> H$
{XE JE AZwÀN>oX H$mo n{‹T>E VWm àíZ g§»`m 1 go 5 Ho$ CÎma Xr{OE : 15=5

AmdV© gmaUr Ho$ d-ãbm°H$ ‘| dJ© 3 go 12 Ho$ VÎd AmVo h¢ Omo g§H«$‘U VÎdm| Ho$ ê$n ‘| OmZo
OmVo h¢ & gm‘mݶ ê$n go BZ VÎdm| H$m Bbo³Q´>m°{ZH$ {dݶmg (n – 1) d1–10 ns1–2 h¡ & BZ
na‘mUwAm| Ho$ Cnm§{V‘ D$Om© ñVa Ho$ d-H$jH$m| ‘| Bbo³Q´>m°Z ^ao OmVo h¢ VWm Bg àH$ma
g§H«$‘U YmVwAm| H$s VrZ n§{³V¶m± AWm©V² 3d, 4d d 5d loUr àmßV hmoVr h¢ & VWm{n Zn, Cd
Am¡a Hg H$mo g§H«$‘U VÎd Zht ‘mZm OmVm h¡ & g§H«$‘U VÎd Hw$N> A{^bmj{UH$ JwU Xem©Vo
h¢ O¡go n[adV©Zr` Am°³grH$aU AdñWmE±, g§Hw$b {Z‘m©U, a§JrZ Am¶Zm| Am¡a {‘lmVwAm| H$m
~ZZm, CËàoaH$s¶ g{H«$¶Vm Am{X & g§H«$‘U YmVwE± (Zn, Cd Am¡a Hg Ho$ AndmXm| Ho$ gmW)
H$R>moa hmoVr h¢ Am¡a BZHo$ JbZm§H$ CÀM hmoVo h¢ &
.56/3/1 2

General Instructions :
Read the following instructions very carefully and strictly follow them :
(i) This question paper comprises four Sections – A, B, C and D. There are
37 questions in the question paper. All questions are compulsory.
(ii) Section A – Questions no. 1 to 20 are very short answer type questions,
carrying 1 mark each. Answer these questions in one word or one sentence.
(iii) Section B – Questions no. 21 to 27 are short answer type questions, carrying
2 marks each.
(iv) Section C – Questions no. 28 to 34 are long answer type-I questions, carrying
3 marks each.
(v) Section D – Questions no. 35 to 37 are long answer type-II questions, carrying
5 marks each.
(vi) There is no overall choice in the question paper. However, an internal choice
has been provided in 2 questions of two marks, 2 questions of three marks and
all the 3 questions of five marks. You have to attempt only one of the choices in
such questions.
(vii) In addition to this, separate instructions are given with each section and
question, wherever necessary.
(viii) Use of calculators and log tables is not permitted.

SECTION A

Read the given passage and answer the questions number 1 to 5 that follow : 15=5

The d-block of the periodic table contains the elements of the groups
3 – 12 and are known as transition elements. In general, the electronic
configuration of these elements is (n – 1) d1–10 ns1–2. The d-orbitals of the
penultimate energy level in their atoms receive electrons giving rise to
the three rows of the transition metals i.e., 3d, 4d and 5d series.
However, Zn, Cd and Hg are not regarded as transition elements.
Transition elements exhibit certain characteristic properties like variable
oxidation states, complex formation, formation of coloured ions and
alloys, catalytic activity, etc. Transition metals are hard (except Zn, Cd
and Hg) and have a high melting point.
.56/3/1 3 P.T.O.

1. Zn, Cd Am¡a Hg g§H«$‘U VÎd ³¶m| Zht ‘mZo OmVo h¢ ?

2. 3d loUr H$m H$m¡Z-gm g§H«$_U YmVw n[adV©Zr¶ Am°³grH$aU AdñWmE± Zht Xem©Vm h¡ ?

3. g§H«$‘U YmVwE± Am¡a CZHo$ ¶m¡{JH$ CËàoaH$s¶ g{H«$¶Vm ³¶m| Xem©Vo h¢ ?

4. g§H«$‘U YmVwAm| Ho$ JbZm§H$ CÀM ³¶m| hmoVo h¢ ?

5. Obr¶ {db¶Z ‘| Cu2+ Am¶Z a§JrZ ³¶m| hmoVm h¡ O~{H$ Zn2+ Am¶Z a§JhrZ hmoVm h¡ &

àíZ g§»`m 6 go 10 EH$ eãX CÎmar¶ h¢ : 15=5

6. Anmobmo A§V[aj H$m¶©H«$‘ ‘| à¶moJ ‘| bmE JE gob H$m Zm‘ {b{IE &
7. 1 ‘mob H2O H$mo O2 ‘| Am°³grH¥$V H$aZo Ho$ {bE {H$VZo Hy$bm°‘ H$s Amdí¶H$Vm hmoVr h¡ ?

8. {H$gr àW‘ H$mo{Q> H$s A{^{H«$¶m Ho$ {bE g‘¶ Ho$ gmW ln[R] Ho$ {dMaU H$mo Xem©Zo dmbo
J«m’$ Ho$ T>mb H$m _mZ {b{IE &
9. Cg S>mBg¡Ho$amBS> H$m Zm‘ {b{IE Omo Ob-AnKQ>Z na ½byH$mog Ho$ Xmo AUw XoVm h¡ &
10. X§V‘§OZ ‘| BñVo‘mb {H$E OmZo dmbo g§píbîQ> An‘mO©H$ Ho$ dJ© H$m Zm‘ {b{IE &
àíZ g§»`m 11 go 15 ~hþ{dH$ënr¶ àíZ h¢ : 15=5

11. {ZåZ{b{IV ‘| go {H$gH$m emoYZ ‘§S>b n[aîH$aU {d{Y Ûmam hmoVm h¡ ?
(A) Cu
(B) Zn
(C) Ge
(D) Sn

12. ao{g_rH$aU hmoVm h¡
(A) SN2 A{^{H«$¶m ‘|
(B) SN1 A{^{H«$¶m ‘|
(C) Z Vmo SN2 A{^{H«$`m ‘| Am¡a Z hr SN1 A{^{H«$¶m ‘|
(D) SN2 A{^{H«$¶m Am¡a SN1 A{^{H«$¶m XmoZm| ‘|

.56/3/1 4

1. Why are Zn, Cd and Hg non-transition elements ?

2. Which transition metal of 3d series does not show variable oxidation
states ?

3. Why do transition metals and their compounds show catalytic activity ?

4. Why are melting points of transition metals high ?

5. Why is Cu2+ ion coloured while Zn2+ ion is colourless in aqueous
solution ?

Questions number 6 to 10 are one word answers : 15=5

6. Name the cell which was used in the Apollo Space Programme.
7. How many coulombs are required for the oxidation of 1 mol of H2O to O2 ?

8. Write the slope value obtained in the plot of ln[R] vs. time for a first
order reaction.

9. Name the disaccharide which on hydrolysis gives two molecules of
glucose.

10. Name the class of the synthetic detergent which is used in toothpaste.

Questions number 11 to 15 are multiple choice questions : 15=5

11. Which of the following is refined by the zone refining process ?
(A) Cu
(B) Zn
(C) Ge
(D) Sn

12. Racemisation occurs in
(A) SN2 reaction
(B) SN1 reaction
(C) Neither SN2 nor SN1 reactions
(D) SN2 reaction as well as SN1 reaction

.56/3/1 5 P.T.O.

13. CHCl3 Am¡a EoëH$mohm°br KOH Ho$ gmW CH2 – NH2 H$mo J‘© H$aZo na ~Zm XþJ©ÝY
XoZo dmbm nXmW© h¡

14. ¶m¡{JH$ CrCl3 . 6H2O H$m EH$ ‘mob AgNO3 {db¶Z Ho$ Am{Y³¶ Ho$ gmW A{^{H«$¶m
H$aHo$ AgCl (s) Ho$ Xmo ‘mob ~ZmVm h¡ & ¶m¡{JH$ H$m g§aMZmË‘H$ gyÌ h¡
(A) [Cr(H2O)5 Cl] Cl2 . H2O

(B) [Cr(H2O)3 Cl3] . 3H2O

(C) [Cr(H2O)4 Cl2] Cl . 2H2O

(D) [Cr(H2O)6] Cl3

15. noßQ>mBS> ~§Y CnpñWV hmoVm h¡
(A) H$m~m}hmBS´>oQ>m| ‘|
(B) {dQ>m{‘Zm| ‘|
(C) àmoQ>rZm| ‘|
(D) a~a ‘|
àíZ g§»`m 16 go 20 Ho$ {bE, Xmo H$WZ {XE JE h¢ {OZ_| EH$ H$mo A{^H$WZ (A) VWm Xÿgao
H$mo H$maU (R) Ûmam A§{H$V {H$`m J`m h¡ & BZ àíZm| Ho$ ghr CÎma ZrMo {XE JE H$moS>m| (i),
(ii), (iii) Am¡a (iv) _| go MwZH$a Xr{OE : 15=5
(i) A{^H$WZ (A) Am¡a H$maU (R) XmoZm| ghr H$WZ h¢ Am¡a H$maU (R), A{^H$WZ (A)
H$s ghr ì¶m»¶m h¡ &
(ii) A{^H$WZ (A) Am¡a H$maU (R) XmoZm| ghr H$WZ h¢, naÝVw H$maU (R),
A{^H$WZ (A) H$s ghr ì¶m»¶m Zht h¡ &
(iii) A{^H$WZ (A) ghr h¡, naÝVw H$maU (R) µJbV H$WZ h¡ &
(iv) A{^H$WZ (A) µJbV h¡, naÝVw H$maU (R) ghr H$WZ h¡ &

.56/3/1 6

13. CH2 – NH2 on heating with CHCl3 and alcoholic KOH gives foul
smell of

14. One mole of CrCl3 . 6H2O compound reacts with excess AgNO3 solution
to yield two moles of AgCl (s). The structural formula of the compound is
(A) [Cr(H2O)5 Cl] Cl2 . H2O
(B) [Cr(H2O)3 Cl3] . 3H2O
(C) [Cr(H2O)4 Cl2] Cl . 2H2O
(D) [Cr(H2O)6] Cl3

15. Peptide linkage is present in
(A) Carbohydrates
(B) Vitamins
(C) Proteins
(D) Rubber
For questions number 16 to 20, two statements are given  one labelled
Assertion (A) and the other labelled Reason (R). Select the correct
answer to these questions from the codes (i), (ii), (iii) and (iv) as given
below : 15=5

(i) Both Assertion (A) and Reason (R) are correct statements, and
Reason (R) is the correct explanation of the Assertion (A).

(ii) Both Assertion (A) and Reason (R) are correct statements, but
Reason (R) is not the correct explanation of the Assertion (A).

(iii) Assertion (A) is correct, but Reason (R) is incorrect statement.

(iv) Assertion (A) is incorrect, but Reason (R) is correct statement.
.56/3/1 7 P.T.O.

16. A{^H$WZ (A) : gmÝÐVm KQ>Zo Ho$ gmW {dÚwV²-AnKQ>ç H$s MmbH$Vm KQ>Vr h¡ &
H$maU (R) : VZwH$aU H$aZo na à{V BH$mB© Am¶VZ ‘| Am¶Zm| H$s g§»¶m ~‹T>Vr h¡ &
17. A{^H$WZ (A) : EoëH$mohm°bm| ‘| C – O – H Am~ÝY H$moU MVwî’$bH$s¶ H$moU go Oam gm
H$‘ hmoVm h¡ &
H$maU (R) : Am°³grOZ na Xmo EH$mH$s Bbo³Q´>m°Z ¶w½‘ Ho$ ~rM à{VH$fu AÝV:{H«$¶m Ho$
H$maU hmoVm h¡ &
18. A{^H$WZ (A) : g§Hw$b [Pt(NH3)4 Cl2]2+ H$s Anojm g§Hw$b [Pt(en)2 Cl2]2+ H$‘
ñWm¶r hmoVm h¡ &
H$maU (R) : g§Hw$b [Pt(en)2 Cl2]2+ H$sboQ> à^md Xem©Vm h¡ &
19. A{^H$WZ (A) : namgaU Xm~ EH$ AUwg§»¶ JwUY‘© h¡ &
H$maU (R) : namgaU Xm~ ‘mobaVm Ho$ AZwH«$‘mZwnmVr hmoVm h¡ &
20. A{^H$WZ (A) : EopëS>hmBS>m| H$s Anojm H$sQ>moZm| H$s A{^{H«$¶merbVm A{YH$ hmoVr h¡ &
H$maU (R) : EopëS>hmBS>m| H$s VwbZm ‘| H$sQ>moZm| ‘| H$m~m}{Zb H$m~©Z H$‘ Bbo³Q´>m°ZamJr
hmoVm h¡ &
IÊS> I
21. Xr JB© A{^{H«$¶m
A + 3B  2C
‘|, C Ho$ ~ZZo H$m doJ 2·5  10–4 mol L–1 s–1 h¡ &
n[aH${bV H$s{OE :
(i) A{^{H«$¶m H$m doJ, Am¡a
(ii) B Ho$ bwßV hmoZo H$m doJ & 2

22. {ZåZ{b{IV H$s ^y{‘H$m {b{IE :
(i) Eobw{‘{Z¶‘ Ho$ {ZîH$f©U ‘| NaAlF4 H$s 1
(ii) Ni Ho$ emoYZ ‘| CO H$s 1
AWdm
~m°³gmBQ> A¶ñH$ Ho$ {ZjmbZ Ûmam ewÕ Eobw{‘Zm àmßV H$aZo go gå~Õ amgm¶{ZH$ g‘rH$aU|
{b{IE & 2
.56/3/1 8

16. Assertion (A) : Conductivity of an electrolyte decreases with decrease in
concentration.
Reason (R) : Number of ions per unit volume increases on dilution.

17. Assertion (A) : The C – O – H bond angle in alcohols is slightly less than
the tetrahedral angle.
Reason (R) : This is due to the repulsive interaction between the two
lone electron pairs on oxygen.

18. Assertion (A) : [Pt(en)2 Cl2]2+ complex is less stable than
[Pt(NH3)4 Cl2]2+ complex.
Reason (R) : [Pt(en)2 Cl2]2+ complex shows chelate effect.

19. Assertion (A) : Osmotic pressure is a colligative property.
Reason (R) : Osmotic pressure is directly proportional to molarity.

20. Assertion (A) : Reactivity of ketones is more than aldehydes.
Reason (R) : The carbonyl carbon of ketones is less electrophilic as
compared to aldehydes.

SECTION B

21. In the given reaction
A + 3B  2C,
the rate of formation of C is 2·5  10–4 mol L–1 s–1.
Calculate the
(i) rate of reaction, and
(ii) rate of disappearance of B. 2

22. Write the role of the following :
(i) NaAlF4 in the extraction of Aluminium 1

(ii) CO in the refining of Ni 1
OR
Write the chemical equations involved in the leaching of bauxite ore to
prepare pure alumina. 2
.56/3/1 9 P.T.O.

23. ^m¡{VH$ A{YemofU Am¡a agmoemofU Ho$ ~rM Xmo AÝVa {b{IE & 2

AWdm

à˶oH$ Ho$ {bE Cn¶w³V CXmhaU g{hV {ZåZ{b{IV nXm| H$mo n[a^m{fV H$s{OE : 2

(i) ghMmar H$mobm°BS>
(ii) O/W B‘ëeZ (nm¶g)

24. (a) g§Hw$b [CoF6]3 – H$m AmB ¶y nr E gr Zm‘ Am¡a g§H$aU {b{IE &
({X¶m J`m h¡ : Co H$m na‘mUw H«$‘m§H$ = 27)
(b) g§Hw$b [Co(en)2 Cl2]2+ Ûmam {H$g àH$ma H$s g‘md¶dVm Xem©B© OmVr h¡ ? Bg
g§Hw$b Ho$ Cg g‘md¶d H$s g§aMZm H$m Zm‘ {b{IE Omo Y«wdU KyU©H$ hmo & 2

25. H$maU Xr{OE : 2

(i) Xm‹T>r ~ZmZo Ho$ gm~wZ ‘| p½bgam°b hmoVm h¡ &
(ii) à{VAåbm| H$m Cn¶moJ A{YH$ g‘¶ VH$ Zht H$aZm Mm{hE &

26. {ZåZ{b{IV nXm| H$s n[a^mfm {b{IE : 2

(i) Amo{bJmog¡Ho$amBS>
(ii) And¥V eH©$am

27. {ZåZ{b{IV A{^{H«$¶m Ho$ CËnmXm| H$mo {b{IE :

6 XeF4 + 12 H2O 

³¶m ¶h A{^{H«$¶m Ag‘mZwnmVZ A{^{H«$¶m h¡ ? AnZo CÎma Ho$ g‘W©Z ‘| H$maU Xr{OE & 2
.56/3/1 10

23. Write two differences between physisorption and chemisorption. 2

OR

Define the following terms with a suitable example of each : 2

(i) Associated colloids

(ii) O/W emulsion

24. (a) Write the IUPAC name and hybridisation of the complex [CoF6]3–.

(Given : Atomic number of Co = 27)

(b) What type of isomerism is shown by the complex [Co(en)2 Cl2]2+ ?

Name the structure of an isomer of this complex which is optically
active. 2

25. Give reasons : 2

(i) Shaving soaps contain glycerol.

(ii) Antacids should not be used for longer time.

26. Define the following terms : 2

(i) Oligosaccharides

(ii) Invert sugar

27. Write the products of the following reaction :

6 XeF4 + 12 H2O 

Is this reaction a disproportionation reaction ? Give reasons in support of
your answer. 2

.56/3/1 11 P.T.O.

IÊS> J
28. 298 K na Xr JB© A{^{H«$¶m Ho$ {bE A{YH$V‘ H$m¶© Am¡a log Kc n[aH${bV H$s{OE : 3

Ni (s) + 2 Ag+ (aq)  Ni2+ (aq) + 2 Ag (s)
{X¶m J`m h¡ :
Eo 2  = – 0·25 V, Eo  = + 0·80 V
Ni / Ni Ag / Ag

1 F = 96500 C mol–1

29. {H$gr àW‘ H$mo{Q> H$s A{^{H«$¶m H$mo 40% nyU© hmoZo ‘| 80 {‘ZQ> bJVo h¢ & doJ pñWam§H$ (k)
H$m ‘mZ n[aH${bV H$s{OE & {H$VZo g‘¶ ‘| A{^{H«$¶m 90% nyU© hmoJr ? 3
[ {X`m J`m h¡ : log 2 = 0·3010, log 3 = 0·4771, log 4 = 0·6021, log 5 = 0·6771,
log 6 = 0·7782]

30. {ZåZ{b{IV ~hþbH$m| ‘| EH$bH$m| Ho$ Zm‘ Am¡a g§aMZmE± {b{IE : 3
(i) ã¶yZm-S
(ii) ZmBbm°Z-6,6
(iii) ~¡Ho$bmBQ>

31. {ZåZ{b{IV A{^{H«$¶mAm| Ho$ ‘w»¶ CËnmX/CËnmXm| H$mo {b{IE : 3

.56/3/1 12

SECTION C

28. Calculate the maximum work and log Kc for the given reaction at 298 K : 3

Ni (s) + 2 Ag+ (aq)  Ni2+ (aq) + 2 Ag (s)
Given :
Eo 2  = – 0·25 V, Eo  = + 0·80 V
Ni / Ni Ag / Ag

1 F = 96500 C mol–1

29. A first order reaction is 40% complete in 80 minutes. Calculate the value
of rate constant (k). In what time will the reaction be 90% completed ? 3

[Given : log 2 = 0·3010, log 3 = 0·4771, log 4 = 0·6021, log 5 = 0·6771,
log 6 = 0·7782]

30. Write the names and structures of the monomers in the following
polymers : 3

(i) Buna-S

(ii) Nylon-6,6

(iii) Bakelite

31. Write the major product(s) of the following reactions : 3

.56/3/1 13 P.T.O.

32. (a) {ZåZ{b{IV A{^{H«$¶m H$s {H«$¶m{d{Y {b{IE :
H
2 CH3CH2OH  CH3CH2OCH2CH3 + H2O
413 K

(b) ³¶y‘rZ go µ\$sZm°b H$m {daMZ {b{IE & 2+1=3
AWdm
Amn {ZåZ{b{IV n[adV©Z H¡$go gånÞ H$a|Jo : 3
(i) gmo{S>¶‘ ’$sZm°³gmBS> go o-hmBS´>mo³gr~oݵOmoBH$ Aåb
(ii) EogrQ>moZ go àmonrZ
(iii) µ\$sZm°b go ³bmoamo~oݵOrZ
33. {Z{‘©V CËnmXm| H$mo {b{IE O~ (CH3)3 C – CHO {ZåZ{b{IV A{^H$‘©H$m| Ho$ gmW
A{^{H«$¶m H$aVm h¡ : 3

(i) VZw NaOH H$s CnpñW{V ‘| CH3COCH3
(ii) HCN
(iii) gmÝÐ NaOH
34. à˶oH$ Ho$ {bE Cn¶w³V CXmhaU XoH$a Ðd{damJr Am¡a ÐdamJr gm°b H$mo n[a^m{fV H$s{OE &
Ðd{damJr gm°b H$s VwbZm ‘| ÐdamJr gm°b H$m ñH§$XZ H${R>Z ³¶m| hmoVm h¡ ? 3
AWdm
{ZåZ{b{IV nXm| H$mo n[a^m{fV H$s{OE : 3
(i) AmH$ma-daUmË‘H$ CËàoaU
(ii) H«$mâQ> Vmn
(iii) noßQ>Z (noßQ>mBµOoeZ)

IÊS> K
35. (a) H$maU Xr{OE : 3
(i) µOrZm°Z H$s ^m±{V hr{b¶‘ ¶m¡{JH$ Zht ~ZmVr &
(ii) HOCl H$s Anojm HClO4 à~bVa Aåb h¡ &
(iii) J§YH$ EH$ ~hþna‘mUwH$ R>mog h¡ O~{H$ Am°³grOZ {Ûna‘mUwH$ J¡g h¡ &

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32. (a) Write the mechanism of the following reaction :
H
2 CH3CH2OH  CH3CH2OCH2CH3 + H2O
413 K

(b) Write the preparation of phenol from cumene. 2+1=3
OR
How can you convert the following : 3
(i) Sodium phenoxide to o-hydroxybenzoic acid
(ii) Acetone to propene
(iii) Phenol to chlorobenzene

33. Write the products formed when (CH3)3 C – CHO reacts with the

following reagents : 3
(i) CH3COCH3 in the presence of dilute NaOH

(ii) HCN

(iii) Conc. NaOH

34. Define Lyophobic and Lyophilic sol with a suitable example of each. Why
is coagulation of Lyophilic sol difficult as compared to Lyophobic sol ? 3
OR
Define the following terms : 3
(i) Shape-selective catalysis
(ii) Kraft temperature
(iii) Peptization

SECTION D

35. (a) Give reasons : 3

(i) Helium does not form compounds like Xenon.
(ii) HClO4 is a stronger acid than HOCl.

(iii) Sulphur is a polyatomic solid whereas Oxygen is a diatomic
gas.
.56/3/1 15 P.T.O.

(b) ¶h Xem©Zo Ho$ {bE {H$ gmÝÐ H2SO4
(i) Am°³grH$maH$, Ed§
(ii) {ZO©bZ H$_©H$ H$s ^m±{V H$m¶© H$aVm h¡,
à˶oH$ Ho$ {bE CXmhaU Ho$ ê$n _| EH$-EH$ A{^{H«$¶m {b{IE & 2
AWdm
(a) {ZåZ{b{IV Ho$ {bE H$maU Xr{OE :
(i) Cl– Am¶Z H$s Anojm F – Am¶Z H$s Ob¶moOZ EÝW¡ënr A{YH$ hmoVr h¡ & 1
(ii) dJ©-16 Ho$ Am°³gmBS>m| ‘| SO2 EH$ AnMm¶H$ h¡, O~{H$ TeO2 EH$
Am°³grH$maH$ h¡ & 1
(b) F2 H$s Ob Ho$ gmW A{^{H«$¶m {b{IE & Am¶moS>rZ (I2) Ob Ho$ gmW A{^{H«$¶m
³¶m| Zht H$aVr ? 1+1
(c) XeF2 H$s g§aMZm ~ZmBE & 1
36. (a) H$maU Xr{OE : 3
(i) ¶Ú{n  NH2 g‘yh Bbo³Q´>m°ZamJr à{VñWmnZ A{^{H«$¶mAm| ‘| Am°Wm} Ed§
n¡am {ZX}eH$ hmoVm h¡ {’$a ^r Eo{ZbrZ ZmBQ´>moH$aU Ûmam ¶WoîQ> _mÌm ‘|
‘oQ>m-ZmBQ´>moEo{ZbrZ XoVr h¡ &
(ii) Obr¶ {db¶Z ‘| (CH3)3 N H$s Anojm (CH3)2 NH A{YH$ jmaH$s¶
hmoVm h¡ &
(iii) ewÕ àmW{‘H$ Eo‘rZm| Ho$ {daMZ Ho$ {bE EopëH$b h¡bmBS>m| H$m
Eo‘moZr-AnKQ>Z EH$ AÀN>r {d{Y Zht h¡ &
(b) {ZåZ{b{IV Ho$ ‘ܶ {d^oX H$s{OE : 2
(i) CH3CH2NH2 Am¡a (CH3CH2)2 NH
(ii) Eo{ZbrZ Am¡a CH3NH2
AWdm
(a) {ZåZ{b{IV A{^{H«$¶mAm| ‘| A Am¡a B H$s g§aMZmE± {b{IE :
 – CuCN H 2O / H 
(i) C6H5 N 2 Cl  A   B 1

NH3 NaOBr
(ii) CH3COOH   A  B 1

(b) ‘o{Wb Eo_rZ H$s ~oݵOm°¶b ³bmoamBS> Ho$ gmW amgm¶{ZH$ A{^{H«$¶m {b{IE Am¡a
àmßV CËnmX H$m AmB ¶y nr E gr Zm‘ {b{IE & 1+1
(c) {ZåZ{b{IV H$mo CZHo$ pKb ‘mZm| Ho$ ~‹T>Vo hþE H«$‘ ‘| ì¶dpñWV H$s{OE : 1
C6H5NH2, NH3, C2H5NH2, (C2H5)2 NH

.56/3/1 16

(b) Write one reaction as an example of each, to show that
conc. H2SO4 acts as
(i) an oxidising agent, and
(ii) a dehydrating agent. 2
OR
(a) Account for the following :
(i) Hydration enthalpy of F – ion is more than Cl – ion. 1
(ii) SO2 is a reducing agent, whereas TeO2 is an oxidising agent
in group-16 oxides. 1
(b) Write the reaction of F2 with water. Why does I2 not react with
water ? 1+1
(c) Draw the structure of XeF2. 1

36. (a) Give reasons : 3
(i) Although – NH2 group is o/p directing in electrophilic
substitution reactions, yet aniline, on nitration gives good
yield of m-nitroaniline.
(ii) (CH3)2 NH is more basic than (CH3)3 N in an aqueous
solution.
(iii) Ammonolysis of alkyl halides is not a good method to
prepare pure primary amines.
(b) Distinguish between the following : 2
(i) CH3CH2NH2 and (CH3CH2)2 NH
(ii) Aniline and CH3NH2
OR
(a) Write the structures of A and B in the following reactions :

 CuCN H O /H
(i) C6H5 N 2 Cl–  A 2  B 1
NH3 NaOBr
(ii) CH3COOH   A  B 1


(b) Write the chemical reaction of methyl amine with benzoyl chloride
and write the IUPAC name of the product obtained. 1+1

(c) Arrange the following in the increasing order of their pKb values : 1
C6H5NH2, NH3, C2H5NH2, (C2H5)2 NH

.56/3/1 17 P.T.O.

37. (a) {H$gr {db¶Z ‘| 5·85 g NaCl (‘moba Ð춑mZ = 58·5 g mol–1) à{V brQ>a
{db¶Z {dÚ‘mZ h¡ & BgH$m 27C na namgaU Xm~ 4·75 dm¶w‘§S>b (atm) h¡ & Bg
{db¶Z ‘| NaCl H$s {d¶moOZ ‘mÌm n[aH${bV H$s{OE & 3
({X¶m J`m h¡ : R = 0·082 L atm K–1 mol–1)
(b) hoZar {Z¶‘ {b{IE & JmoVmImoam| Ûmam à¶w³V dm¶w H$mo hr{b¶‘ go VZwH$aU H$aHo$
Q>¡ÝH$m| ‘| ³¶m| ^am OmVm h¡ ? 1+1
AWdm
(a) F – CH2 – COOH (‘moba Ð춑mZ = 78 g mol–1) Ho$ 19·5 g H$mo 500 g Ob
‘| KmobZo na {h‘m§H$ ‘| 1C H$m AdZ‘Z XoIm J¶m & F – CH2 – COOH H$s
{d¶moOZ ‘mÌm n[aH${bV H$s{OE & 3
[ {X¶m J`m h¡ : Ob Ho$ {bE Kf = 1·86 K kg mol–1]

(b) H$maU Xr{OE :
(i) 0·1 M KCl H$m ³dWZm§H$ 0·1 M ½byH$mog H$s VwbZm ‘| CÀMVa hmoVm h¡ & 1
(ii) bdU {‘bmZo na ‘m§g A{YH$ g‘¶ VH$ n[aa{jV ahVm h¡ & 1

.56/3/1 18

37. (a) A solution contains 5·85 g NaCl (Molar mass = 58·5 g mol–1) per
litre of solution. It has an osmotic pressure of 4·75 atm at 27C.
Calculate the degree of dissociation of NaCl in this solution. 3
(Given : R = 0·082 L atm K–1 mol–1)

(b) State Henry’s law. Why is air diluted with helium in the tanks
used by scuba divers ? 1+1
OR

(a) When 19·5 g of F – CH2 – COOH (Molar mass = 78 g mol–1) is
dissolved in 500 g of water, the depression in freezing
point is observed to be 1C. Calculate the degree of dissociation of
F – CH2 – COOH. 3
[Given : Kf for water = 1·86 K kg mol–1]

(b) Give reasons :
(i) 0·1 M KCl has higher boiling point than 0·1 M Glucose. 1
(ii) Meat is preserved for a longer time by salting. 1

.56/3/1 19 P.T.O.