CBSE Class 12 Question Paper 2024 Chemistry

CBSE

Series SQR1P/1 SET-1
àíZ-nÌ H$moS>
Q.P. Code 56/1/1
amob Z§. narjmWu àíZ-nÌ H$moS> >H$mo CÎma-nwpñVH$m Ho$
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>33 àíZ h¢ & contains 33 questions.

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

:3 : 70
Time allowed : 3 hours Maximum Marks : 70

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

:
:
(i) 33
(ii)
(iii) 1 16 1

(iv) 17 21 2

(v) 22 28 3
(vi) 29 30 4
(vii) 31 33 5
(viii)

(ix)
(x)

IÊS> H$
1 16 1 16 1=16

1. {ZåZ{b{IV àW_ g§H«$_U loUr Ho$ VÎ
Ano{jV h¡ ?
(A) Am`aZ (Z = 26)
(B) _¢JZrµO (Z = 25)
(C) H«$mo{_`_ (Z = 24)
(D) d¡Zo{S>`_ (Z = 23)
2. {ZåZ{b{IV `m¡{JH$m| _| go H$m¡Z-gm H«$mo{_H$ EoZhmBS´>mBS> (CrO3) Ûmam Am°
H$sQ>moZ XoJm ?
(A) (CH3)2CH CH2OH

(B) CH3CH2CH2OH
(C) (CH3)3C OH
(D) CH3 CH2 CH CH3
|
OH
56/1/1-11 2

General Instructions :
Read the following instructions carefully and follow them :
(i) This question paper contains 33 questions. All questions are compulsory.
(ii) This question paper is divided into five sections Section A, B, C, D and E.
(iii) Section A questions number 1 to 16 are multiple choice type questions. Each
question carries 1 mark
(iv) Section B questions number 17 to 21 are very short answer type questions.
Each question carries 2 marks
(v) Section C questions number 22 to 28 are short answer type questions. Each
question carries 3 marks
(vi) Section D questions number 29 and 30 are case-based questions. Each
question carries 4 marks
(vii) Section E questions number 31 to 33 are long answer type questions. Each
question carries 5 marks
(viii) There is no overall choice given in the question paper. However, an internal
choice has been provided in few questions in all the sections except Section A.
(ix) Kindly note that there is a separate question paper for Visually Impaired
candidates.
(x) Use of calculators is not allowed.

SECTION A
Questions no. 1 to 16 are Multiple Choice type Questions, carrying 1 mark
each. 16 1=16
1. Which one of the following first row transition elements is expected to
have the highest third ionization enthalpy ?
(A) Iron (Z = 26)
(B) Manganese (Z = 25)
(C) Chromium (Z = 24)
(D) Vanadium (Z = 23)
2. Which of the following compounds will give a ketone on oxidation with
chromic anhydride (CrO3) ?
(A) (CH3)2CH CH2OH
(B) CH3CH2CH2OH
(C) (CH3)3C OH
(D) CH3 CH2 CH CH3
|
OH
56/1/1-11 3 P.T.O.

3. DNA Ho$ VrZ KQ>H$m| _| go Xmo KQ>H$ -D-2- jmaH$ hmoVo
h¢ & Vrgam KQ>H$ h¡ :
(A) EoS>oZrZ

(B) µ\$m°ñµ\$mo[aH$ Aåb

(C) gëâ`y[aH$ Aåb

(D) `yao{gb

4. {H$gr {dÚwV-AnKQ²>` H$m {dbm`H$ _| g§JwUZ hmoZo na, dmÝQ> hm°\$ H$maH$ :

(A) gX¡d EH$ go A{YH$ hmoVm h¡

(B) H$m G$UmË_H$ _mZ hmoVm h¡

(C) H$m eyÝ` _mZ hmoVm h¡

(D) gX¡d EH$ go H$_ hmoVm h¡

5. A{^{H«$`m X + 2Y P Ho$ {bE, doJ {Z`_ H$m AdH$b ê$n g_rH$aU h¡ :

2d P d Y
(A) =
dt dt

d P d X
(B) =
dt dt

+d X d P
(C) =
dt dt

2d Y +d P
(D) =
dt dt

56/1/1-11 4

3. Two among the three components of DNA are -D-2-deoxyribose and a
heterocyclic base. The third component is :

(A) Adenine

(B) Phosphoric acid

(C) Sulphuric acid

(D) Uracil

4. For an electrolyte undergoing association in a solvent, the v
factor :

(A) is always greater than one

(B) has negative value

(C) has zero value

(D) is always less than one

5. For the reaction X + 2Y P, the differential form equation of the rate
law is :

2d P d Y
(A) =
dt dt

d P d X
(B) =
dt dt

+d X d P
(C) =
dt dt

2d Y +d P
(D) =
dt dt

56/1/1-11 5 P.T.O.

6. dh `m¡{JH$ Omo SN1 A{^{H«$`m AË`{YH$ erK«Vm go H$aVm h¡, dh h¡ :

7. Eogr{Q>H$ Aåb PCl5 Ho$ gmW A{^{H«$`m H$aHo$ XoVm h¡ :
(A) Cl CH2 COCl

(B) Cl CH2 COOH

(C) CH3 COCl

(D) CCl3 COOH

8. EopëS>hmBS> go gm`ZmohmB{S´>Z H$m ~ZZm EH$ CXmhaÊm h¡ :
(A) Zm{^H$amJr `moJO H$m
(B)

(C) Zm{^H$amJr à{VñWmnZ H$m
(D)

9. Ama}{ZAg g_rH$aU _| O~ 1/T Ho$ gmW log k H$m J«m\$ ItMm OmVm h¡, Vmo EH$ grYr
aoIm àmá hmoVr h¡ {OgH$r :
(A) T>mb A h¡ Am¡a A§V:I§S> Ea h¡ &
R
Ea
(B) T>mb A h¡ Am¡a A§V:I§S> h¡ &
R
Ea
(C) T>mb h¡ Am¡a A§V:I§S> log A h¡ &
RT
Ea
(D) T>mb h¡ Am¡a A§V:I§S> log A h¡ &
2·303 R

56/1/1-11 6

6. The compound which undergoes S N1 reaction most rapidly is :

7. Acetic acid reacts with PCl5 to give :

(A) Cl CH2 COCl

(B) Cl CH2 COOH
(C) CH3 COCl
(D) CCl3 COOH

8. The formation of cyanohydrin from an aldehyde is an example of :
(A) nucleophilic addition

(B) electrophilic addition
(C) nucleophilic substitution
(D) electrophilic substitution

9. In the Arrhenius equation, when log k is plotted against 1/T, a straight
line is obtained whose :
A
(A) slope is and intercept is Ea.
R
Ea
(B) slope is A and intercept is .
R
Ea
(C) slope is and intercept is log A.
RT
Ea
(D) slope is and intercept is log A.
2·303 R

56/1/1-11 7 P.T.O.

10. EopëH$b h¡bmBS> H$s gmo{S>`_ EoëH$ B©Wa ~ZZo H$mo H$hVo h¢ :
(A) dwQ²>©µO A{^{H«$`m
(B) amB_a-Q>r_Z A{^{H«$`m
(C) {d{b`ågZ g§íbofU
(D) H$moë~o A{^{H«$`m
11. {ZåZ{b{IV EoëH$mohm°bm| H$m gmÝÐ gëâ`y[aH$ Aåb Ûmam {ZO©bZ H$s gwJ_Vm H$m ghr
H«$_ h¡ :
(A) (CH3)3C OH > (CH3)2CH OH > CH3CH2 OH

(B) (CH3)2CH OH > CH3CH2 OH > (CH3)3C OH
(C) CH3CH2 OH > (CH3)2CH OH > (CH3)3C OH
(D) (CH3)2CH OH > (CH3)3C OH > CH3CH2 OH

12. ½byH$mog Ho$ H$m¡Z-go àH$m`m©Ë_H$ g_yh Amng _| {H«$`m H$aHo$ MH«$s` h¡_rEogrQ>¡b ~ZmH$a
nmBa¡Zmog g§aMZm H$m {Z_m©U H$aVo h¢ ?
(A) C 4 na EopëS>hmB
(B) C 5 na EopëS>hm
(C) C 4 na H$sQ>m

(D) C 5 na H$sQ> g_yh

13 16 (A)
(R)
(A), (B), (C) (D)

(A) A{^H$WZ (A) Am¡a H$maU (R) XmoZm| ghr h¢ Am¡a H$maU (R), A{^H$WZ (A) H$s
ghr ì¶m»¶m H$aVm h¡ &
(B) A{^H$WZ (A) Am¡a H$maU (R) XmoZm| ghr h¢, naÝVw H$maU (R), A{^H$WZ (A) H$s
ghr ì¶m»¶m H$aVm h¡ &
(C) A{^H$WZ (A) ghr h¡, naÝVw H$maU (R) µJbV h¡ &
(D) A{^H$WZ (A) µJbV h¡, naÝVw H$maU (R) ghr h¡ &
56/1/1-11 8

10. The reaction of an alkyl halide with sodium alkoxide forming ether is
known as :
(A) Wurtz reaction
(B) Reimer-Tiemann reaction
(C) Williamson synthesis
(D) Kolbe reaction

11. The correct order of the ease of dehydration of the following alcohols by
the action of conc. H2SO4 is :

(A) (CH3)3C OH > (CH3)2CH OH > CH3CH2 OH
(B) (CH3)2CH OH > CH3CH2 OH > (CH3)3C OH
(C) CH3CH2 OH > (CH3)2CH OH > (CH3)3C OH
(D) (CH3)2CH OH > (CH3)3C OH > CH3CH2 OH

12. Which functional groups of glucose interact to form cyclic hemiacetal
leading to pyranose structure ?
(A) Aldehyde group and hydroxyl group at C 4
(B) Aldehyde group and hydroxyl group at C 5
(C) Ketone group and hydroxyl group at C 4
(D) Ketone group and hydroxyl group at C 5

For Questions number 13 to 16, two statements are given one labelled
as Assertion (A) and the other labelled as Reason (R). Select the correct
answer to these questions from the codes (A), (B), (C) and (D) as given
below.
(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the
correct explanation of the Assertion (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not
the correct explanation of the Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.

56/1/1-11 9 P.T.O.

13. (A) : Ob _| NaCl {_bmE OmZo na {h_m§H$ _| AdZ_Z ào{jV {H$`m OmVm h¡ &
(R) : Ob _| NaCl {d`mo{OV hmo OmVm h¡ &

14. (A) : Zr Am¡a Hf h¡ &
(R) : b¡ÝWoZm°`S> AmH§w$MZ Ho$ H$maU Zr Am¡a Hf H$s {ÌÁ`mE± g_mZ hmoVr h¢ &

15. (A) : Cl CH2 COOH H$s Anojm EWoZm°BH$> Aåb H$m pKa _mZ {ZåZVa

hmoVm h¡ &
(R) : ( I) à^md Xem©Vr h¡ {Oggo
Cl CH2 COOH H$ &

16. (A) : A_mo{Z`m H$s VwbZm _| Eo{ZbrZ à~bVa jmaH$ h¡ &
(R) : Eo{ZbrZ _| ZmBQ´>moOZ na_mUw na CnpñWV Agh^m ,
AZwZmX Ho$ H$maU àmoQ>m°ZZ Ho$ {bE H$_ CnbãY hmoVm h¡ &

IÊS> I
2+
17. Am Fe Am`Z H$s gm§ÐVm 0·01 M h¡ &
o
(298 K na E Fe2+/Fe = 0·45 V) [{X`m J`m h¡ : log 10 = 1] 2

18. A{^{H«$`m H$s AmpÊdH$Vm n[a^m{fV H$s{OE & H$moB© EH$ n[apñW{V ~VmBE {Og_| EH$
{ÛAmpÊdH$ A{^{H«$`m J{VH$V: àW_ H$mo{Q> H$m AZwgaU H$aVr h¡ & 2

19. D-½byH$mog H$mo {ZåZ{b{IV A{^H$_©H$m| Ho$ gmW A{^H¥$V {H$`m OmVm
h¡ ? 1+1=2

(H$) HI (I) gmÝÐ HNO3
56/1/1-11 10

13. Assertion (A) : When NaCl is added to water a depression in freezing
point is observed.

Reason (R) : NaCl undergoes dissociation in water.

14. Assertion (A) : Separation of Zr and Hf is difficult.

Reason (R) : Zr and Hf have similar radii due to lanthanoid contraction.

15. Assertion (A) : The pKa of ethanoic acid is lower than that of
Cl CH2 COOH.

Reason (R) : Chlorine shows electron withdrawing ( I) effect which
increases the acidic character of Cl CH2 COOH.

16. Assertion (A) : Aniline is a stronger base than ammonia.

Reason (R) : The unshared electron pair on nitrogen atom in aniline
becomes less available for protonation due to resonance.

SECTION B

17. Calculate the potential of Iron electrode in which the concentration of
Fe2+ ion is 0·01 M.
o
(E Fe2+/Fe = 0·45 V at 298 K)
[Given : log 10 = 1] 2

18. Define molecularity of the reaction. State any one condition in which a

bimolecular reaction may be kinetically of first order. 2

19. What happens when D-glucose is treated with the following reagents ? 1+1=2

(a) HI (b) Conc. HNO3
56/1/1-11 11 P.T.O.

20. (H$) {ZåZ{b{IV àË`oH$ A{^{H«$`m Ho$ _w»` _moZmoh¡bmo CËnmXm| H$s g§aMZmE± ~ZmBE : 1+1=2

(ii)

AWdm

(I) {ZåZ{b{IV Ho$ {bE H$maU Xr{OE : 1+1=2

(i) J«rÝ`ma A{^H$_©H$ H$m {daMZ {ZO©br` AdñWmAm| _| H$aZm Mm{hE &

(ii) EopëH$b h¡bmBS> Obr` KOH Ho$ gmW EoëH$mohm°b XoVo h¢ O~{H$ EoëH$mohm°br

KOH H$s CnpñW{V _| EoëH$sZ {Z{_©V hmoVo h¢ &

21. amgm`{ZH$ g_rH$aU {b{IE O~ : 1+1=2

(H$) ã`yQ>oZ-2-AmoZ H$mo Zn(Hg) Am¡a gmÝÐ HCl Ho$ gmW A{^H¥$V {H$`m OmVm h¡ &

(I) ~oݵO¡pëS>hmBS> Ho$ Xmo AUwAm| H$mo gmÝÐ NaOH Ho$ gmW A{^H¥$V {H$`m OmVm h¡ &

IÊS> J

22. O~ {H$gr MmbH$Vm gob H$mo 0·05 M KCl {db`Z go ^am OmVm h¡, Vmo 25ºC na BgH$m
à{VamoY 100 Amo_ h¡ & O~ Cgr gob H$mo 0·02 M AgNO3 {db`Z go ^am J`m, Vmo
à{VamoY 90 Amo_ Wm & AgNO3 {db`Z H$s MmbH$Vm Am¡a _moba MmbH$Vm n[aH${bV
H$s{OE & 3

2 1 1
({X`m J`m h¡ : 0·05 M KCl {db`Z H$s MmbH$Vm = 1·35 10 ohm cm )

56/1/1-11 12

20. (a) Draw the structures of major monohalo products in each of the
following reactions : 1+1=2

(ii)

OR

(b) Give reasons for the following : 1+1=2

(i) Grignard reagent should be prepared under anhydrous
conditions.

(ii) Alkyl halides give alcohol with aqueous KOH whereas in the

presence of alcoholic KOH, alkenes are formed.

21. Write the chemical equation when : 1+1=2

(a) Butan-2-one is treated with Zn(Hg) and conc. HCl.

(b) Two molecules of benzaldehyde are treated with conc. NaOH.

SECTION C

22. When a certain conductivity cell was filled with 0·05 M KCl solution, it

has a resistance of 100 ohm at 25ºC. When the same cell was filled with
0·02 M AgNO3 solution, the resistance was 90 ohm. Calculate the

conductivity and molar conductivity of AgNO3 solution. 3
2 1 1
(Given : Conductivity of 0·05 M KCl solution = 1·35 10 ohm cm )

56/1/1-11 13 P.T.O.

23. A{^{H«$`m 2NO (g) + Br2 (g) 2NOBr (g) Ho$ {bE {ZåZ{b{IV àma§
àmá hþE :

à`moJ g§»`m [NO]/mol L
1
[Br2]/mol L
1 àma§{^H$ doJ
1 1
(mol L s )
3
1 0·05 0·05 1·0 10
3
2 0·05 0·15 3·0 10
3
3 0·15 0·05 9·0 10

(H$) A{^{H«$`m _|§ NO Am¡a Br2 Ho$ à{V H$mo{Q> ?

(I) doJ pñWam§H$ (k) n[aH${bV H$s{OE &
(J) A{^{H«$`m doJ {ZYm©[aV H$s{OE O~ NO Am¡a Br2 H$s gm§ÐVm H«$_e: 0·4 M Am¡a
0·2 M h¡ & 1+1+1=3

24. (H$) {ZåZ{b{IV Cnghg§`moOZ `m¡{JH$ H$m gyÌ {b{IE :
nmoQ>¡{e`_ Q>o µO§Ho$Q> (II)
(I) hþE H«$_ _| ì`dpñWV
H$s{OE :
[Cr(NH3)5Cl]Cl2, [Cr(NH3)3Cl3], [Cr(NH3)6]Cl3

(J) {ZåZ{b{IV g§Hw$bm| Ûmam àX{e©V g_md`dVm H$s nhMmZ H$s{OE :
(i) [Co(NH3)5NO2]2+
1 1
(ii) [Co(en)3]Cl3 1+1+( + )=3
2 2

25. (H$) {ZåZ{b{IV _| go H$m¡Z-gm Eo{b{bH$ h¡bmBS> h¡ ?
(i) CH3 CH = CH Br

(ii) CH2 = CH CH CH3
|
Br

56/1/1-11 14

23. The following initial rate data were obtained for the reaction :
2NO (g) + Br2 (g) 2NOBr (g)

1 1 Initial Rate
Expt. No. [NO]/mol L [Br2]/mol L
(mol L 1 s 1 )
3
1 0·05 0·05 1·0 10
3
2 0·05 0·15 3·0 10
3 0·15 0·05 9·0 10 3

(a) What is the order with respect to NO and Br2 in the reaction ?

(b) Calculate the rate constant (k).

(c) Determine the rate of reaction when concentration of NO and Br2
are 0·4 M and 0·2 M, respectively. 1+1+1=3

24. (a) Write the formula for the following coordination compound :

Potassium tetrahydroxidozincate (II)

(b) Arrange the following complexes in the increasing order of
conductivity of their solution :
[Cr(NH3)5Cl]Cl2, [Cr(NH3)3Cl3], [Cr(NH3)6]Cl3

(c) Identify the type of isomerism exhibited by the following complexes :

(i) [Co(NH3)5NO2]2+
1 1
(ii) [Co(en)3]Cl3 1+1+( + ) = 3
2 2

25. (a) Which of the following is an allylic halide ?

(i) CH3 CH = CH Br

(ii) CH2 = CH CH CH3
|
Br

56/1/1-11 15 P.T.O.

(I) µOrZ Am¡a 2,4,6-Q´>mB µOrZ _| go H$m¡Z Zm{^H$amJr à{VñWmnZ Ho$
?

(J) C4H9Cl ? 3 1=3

26. (H$) {ZåZ{b{IV A{^{H«$`m H$s {H«$`m{d{Y {b{IE :
H
CH3CH2OH CH2 = CH2
443 K

(I) {ZåZ{b{IV àË`oH$ A{^{H«$`m Ho$ _w»` CËnmX {b{IE :
a) B2 H6
(i) CH3 CH2 CH = CH2
b) 3H 2O2 / OH

(ii)
1+2=3

27. {ZåZ{b{IV Ho$ CÎma Xr{OE : (H$moB© ) 3 1=3

(H$) ?

(I) {H$g àH$ma H$m Am~§Y DNA H$s ?

(J) {ZåZ{b{IV _| go H$m¡Z-gm nm°{bg¡H¡$amBS> h¡ ?
gyH«$mog, ½byH$mog, ñQ>mM©, \
(K) >Ob _| {dbo` {dQ>m{_Z Am¡a dgm _| {dbo` {dQ>m{_Z àË`oH$ H$m EH$-EH$ CXmhaU
Xr{OE &

28. `m¡{JH$ (A) (C6H12O2), LiAlH4 go AnM{`V hmoH$a Xmo `m¡{JH$ (B) Am¡a (C) XoVm h¡ &
`m¡{JH$ (B) PCC (D) XoVm h¡ Omo VZw NaOH Ho$ gmW
A{^H¥$V H$aHo$ VXþnamÝV J_© H$aZo na `m¡{JH$ (E) XoVm h¡ & `m¡{JH$ (E) CËàoaH$s`
hmBS´>moOZZ H$aZo na `m¡{JH$ (C) XoVm h¡ & `m¡{JH$ (D) (F)
XoVm h¡ Omo {H$ EH$jmaH$s` Aåb (AUw ^ma = 60) nm`m J`m & `m¡{JH$m| (A), (B), (C),
1
(D), (E) Am¡a (F) H$s nhMmZ H$s{OE & 6 =3
2
56/1/1-11 16

(b) Out of chlorobenzene and 2,4,6-trinitrochlorobenzene, which is
more reactive towards nucleophilic substitution and why ?
(c) Which isomer of C4H9Cl has the lowest boiling point ? 3 1=3

26. (a) Write the mechanism of the following reaction :

H
CH3CH2OH CH2 = CH2
443 K

(b) Write the main product in each of the following reactions :
a) B2 H6
(i) CH3 CH2 CH = CH2
b) 3H 2O2 / OH

(ii)
1 2=3

27. Answer the following : (any three) 3 1=3

(a) What is peptide linkage ?
(b) What type of bonds hold a DNA double helix together ?

(c) Which one of the following is a polysaccharide ?
Sucrose, Glucose, Starch, Fructose
(d) Give one example each for water-soluble vitamins and fat-soluble
vitamins.

28. Compound (A) (C6H12O2) on reduction with LiAlH4 gives two compounds
(B) and (C). The compound (B) on oxidation with PCC gives compound (D)
which upon treatment with dilute NaOH and subsequent heating gives
compound (E). Compound (E) on catalytic hydrogenation gives compound
(C). The compound (D) is oxidized further to give compound (F) which is
found to be a monobasic acid (Molecular weight = 60). Identify the
1
compounds (A), (B), (C), (D), (E) and (F). 6 =3
2
56/1/1-11 17 P.T.O.

IÊS> K

29. ~¡Q>[a`m± Am¡a BªYZ gob J¡ëdoZr gob Ho$ AË`ÝV Cn`moJr ê$n h¢ & {dÚwV D$Om© Ho$ òmoV Ho$
{bE à`wº$ H$moB© ^r ~¡Q>ar AWdm gob _yb^yV ê$n go J¡ëdoZr gob hmoVm h¡ & VWm{n, {H$gr
~¡Q>ar Ho$ àm`mo{JH$ Cn`moJ Ho$ {bE Bgo hëH$s VWm gwg§~Õ hmoZm Mm{hE Ed§ à`moJ _| bmVo
g_` BgH$s dmoëQ>Vm _| A{YH$ n[adV©Z Zht hmoZm Mm{hE & _w»`V: ~¡Q>[a`m± Xmo àH$ma H$s
hmoVr h¢ àmW{_H$ ~¡Q>[a`m± Am¡a g§Mm`H$ ~¡Q>[a`m± &
àmW{_H$ ~¡Q>[a`m| _|, A{^{H«$`m Ho$db EH$ ~ma hmoVr h¡ VWm Hw$N> g_` VH$ à`moJ Ho$ ~mX
~¡Q>ar {ZpîH«$` hmo OmVr h¡ Ed§ nwZ: à`moJ _| Zht bmB© Om gH$Vr, O~{H$ g§Mm`H$ ~¡Q>[a`m±
nwZ:Amdo{eV H$s Om gH$Vr h¢ &
D$î_r` g§`§Ìm| goo {dÚwV CËnmXZ ~hþV A{YH$ Cn`moJr {d{Y Zht h¡ VWm `h àXÿfU H$m EH$
òmoV h¡ & Bg g_ñ`m Ho$ g_mYmZ Ho$ {bE Eogo J¡ëdo Zr gob A{^H$pënV {H$E JE h¢
{OZ_| BªYZm| H$s XhZ D$Om© H$mo grYo hr {dÚwV D$Om© _| n[ad{V©V {H$`m OmVm h¡ , Am¡a BÝh|
BªYZ gob H$hVo h¢ & Eogo hr EH$ BªYZ gob H$mo Anmobmo A§V[aj H$m`©H«$_ _| à`moJ _| bm`m
J`m Wm &
{ZåZ{b{IV àíZm| Ho$ CÎma Xr{OE :
(H$) àmW{_H$ ~¡Q>[a`m±, g§Mm`H$ ~¡Q>[a`m| go {H$g àH$ma {^Þ hmoVr h¢ ? 1

(I) 1·35 V hmoVm h¡ VWm gånyU© H$m`©-Ad{Y _| pñWa ahVm h¡ &
H$maU Xr{OE & 1

(J) boS> g§Mm`H$ ~¡Q>ar Ho$ nwZ:AmdoeZ ([aMm{OªJ) _| gpå_{bV A{^{H«$`mE± {b{IE & 2

AWdm

(J) AÝ` J¡ëdoZr gobm| H$s Anojm BªYZ gobm| Ho$ Xmo bm^ {b{IE & 2

56/1/1-11 18

SECTION D

The following questions are case-based questions. Read the case carefully and
answer the questions that follow.

29. Batteries and fuel cells are very useful forms of galvanic cell. Any battery
or cell that we use as a source of electrical energy is basically a galvanic
cell. However, for a battery to be of practical use it should be reasonably
light, compact and its voltage should not vary appreciably during its use.
There are mainly two types of batteries primary batteries and
secondary batteries.

In the primary batteries, the reaction occurs only once and after use over
a period of time the battery becomes dead and cannot be reused again,
whereas the secondary batteries are rechargeable.

Production of electricity by thermal plants is not a very efficient method
and is a major source of pollution. To solve this problem, galvanic cells
are designed in such a way that energy of combustion of fuels is directly
converted into electrical energy, and these are known as fuel cells. One
such fuel cell was used in the Apollo space programme.

Answer the following questions :

(a) How do primary batteries differ from secondary batteries ? 1

(b) The cell potential of Mercury cell is 1·35 V, and remains constant
during its life. Give reason. 1

(c) Write the reactions involved in the recharging of the lead storage
battery. 2

OR

(c) Write two advantages of fuel cells over other galvanic cells. 2

56/1/1-11 19 P.T.O.

30. g§`moOH$Vm Am~§Y {gÕm§V (VBT) Cnghg§`moOZ `m¡{JH$m| Ho$ ~ZZo, Mw§~H$s` ì`dhma Am¡a
Á`m{_Vr` AmH¥${V`m| H$m `Wmo{MV ñnîQ>rH$aU XoVm h¡ O~{H$ {H«$ñQ>b joÌ {gÕm§V
Cnghg§`moOZ `m¡{JH$m| _| {dÚ_mZ Ho$ÝÐr` YmVw na_mUw/Am`Z Ho$ d-H$jH$mo§ H$s D$Om© H$s
g_mZVm na {d{^Þ {H«$ñQ>b joÌm| Ho$ à^md ({bJÝS>m| H$mo q~Xþ Amdoe _mZVo hþE CZHo$ Ûmam
àXÎm à^md) na AmYm[aV h¡ & à~b VWm Xþ~©b {H«$ñQ>b joÌm| _| d-H$jH$mo§ Ho$ {dnmQ>Z
(splitting)

{H$ Cnghg§`moOZ `m¡{JH$m| H$m d-d g§H«$_U (transition) Ho$ H$maU hmoVm

h¡ & Cnghg§`moOZ `m¡{JH$m| H$s YmVwH$_© àH«$_m|, {díbofUmË_H$ VWm Am¡fY agm`Z Ho$ joÌ
_| _hÎdnyU© AZwà`moJ h¢ &

{ZåZ{b{IV àíZm| Ho$ CÎma Xr{OE :

(H$) { ? 1

3+
(I) {H«$ñQ>b joÌ {gÕm§V Ho$ AmYma na g§Hw$b Ti(H2O)6] Ho$ ~¢JZr a§J H$m H$maU
Xr{OE & 1

3+
(J) [Cr(NH3)6] AZwMwå~H$s` h¡ O~{H$ [Ni(CN)4]2 à{VMwå~H$s` h¡ & ì`m»`m
H$s{OE, & [na_mUw H«$_m§H$ : Cr = 24, Ni = 28] 2

AWdm

3
(J) [Fe(CN)6] EH$ Am§V[aH$ H$jH$ g§Hw$b h¡ O~{H$ [Fe(H2O)6]3+ ~mø H$jH$
g§Hw$b h¡, ì`m»`m H$s{OE, & [na_mUw H«$_m§H$ : Fe = 26] 2

56/1/1-11 20

30. The Valence Bond Theory (VBT) explains the formation, magnetic

behaviour and geometrical shapes of coordination compounds whereas

for coordination compounds is based on the

effect of different crystal fields (provided by ligands taken as point

charges), on the degeneracy of d-orbital energies of the central metal

atom/ion. The splitting of the d-orbitals provides different electronic

arrangements in strong and weak crystal fields. The crystal field theory

attributes the colour of the coordination compounds to d-d transition of

the electron. Coordination compounds find extensive applications in

metallurgical processes, analytical and medicinal chemistry.

Answer the following questions :

(a) What is crystal field splitting energy ? 1

(b) Give reason for the violet colour of the complex [Ti(H2O)6]3+ on the

basis of crystal field theory. 1

(c) [Cr(NH3)6]3+ is paramagnetic while [Ni(CN) 4]2 is diamagnetic.

Explain why. [Atomic No. : Cr = 24, Ni = 28] 2

OR

(c) Explain why [Fe(CN)6]3 is an inner orbital complex, whereas

[Fe(H2O)6]3+ is an outer orbital complex. 2

[Atomic No. : Fe = 26]

56/1/1-11 21 P.T.O.

IÊS> L>
31. (H$) (i) g_mZ Vmn na O2 J¡g H$s VwbZm _| CO2 J¡g Ob _| A{YH$ {dbo` hmoVr
h¡ & BZ_| go {H$gH$m KH H$m ?

(ii) O~ é{Ya H$mo{eH$mAm| H$mo 0·9% (Ðì`_mZ/Am`VZ) go A{YH$ gmo{S>`_
Ho$ Obr` {db`Z _| aIm OmVm h¡ V~ CZH$m Am_mn (gmBµO)
{H$g àH$ma n[ad{V©V hmoVm h¡ ?

(iii) {H$gr {dÚwV-AnKQ²>` A2B3 H$m 1 _mobb Obr` {db`Z 60% Am`ZrH¥$V
hmoVm h¡ & 1+1+3=5

({X`m J`m h¡ : Ob Ho$ {bE Kb = 0·52 K kg mol 1)

AWdm

(I) (i) 25ºC na A Am¡a B Ho$ dmîn Xm~ H«$_e: 75 mm Hg Am¡a 25 mm Hg
h¢ & `{X A Am¡a B H$mo Bg àH$ma {_bm`m OmE {H$ {_lU _| A H$m
_mob-A§e 0·4 h¡, Vmo B H$s dmînr` àmdñWm _| _mob-A§e H$s JUZm
H$s{OE &

(ii) AUwg§»` JwUY_© H$mo n[a^m{fV H$s{OE & ~¥hXmUwAm| Ho$ _moba Ðì`_mZ kmV
H$aZo Ho$ {bE H$m¡Z-go AUwg§»` JwUY_© H$mo dar`Vm Xr OmVr h¡ ?

(iii) m § Zht
hmoVo h¢ ? 2+2+1=5

32. {ZåZ{b{IV {H$Ýht àíZm| Ho$ CÎma Xr{OE : 5 1=5

(H$) N,N-S>mBE{Wb-~oݵOrZgë\$moZ¡_mBS> jma _| A{dbo` hmoVm h¡ & H$maU Xr{OE &

(I) Eo{ZbrZ \«$sS>ob- ?

56/1/1-11 22

SECTION E

31. (a) (i) At the same temperature, CO2 gas is more soluble in water
than O2 gas. Which one of them will have higher value of
KH and why ?

(ii) How does the size of blood cells change when placed in an
aqueous solution containing more than 0·9% (mass/volume)
sodium chloride ?

(iii) 1 molal aqueous solution of an electrolyte A 2B3 is 60%
ionized. Calculate the boiling point of the solution. 1+1+3=5

(Given : Kb for H2O = 0·52 K kg mol 1)

OR

(b) (i) The vapour pressures of A and B at 25ºC are 75 mm Hg and
25 mm Hg, respectively. If A and B are mixed such that the
mole fraction of A in the mixture is 0·4, then calculate the
mole fraction of B in vapour phase.

(ii) Define colligative property. Which colligative property is
preferred for the molar mass determination of
macromolecules ?

(iii) Why are equimolar solutions of sodium chloride and glucose
not isotonic ? 2+2+1=5

32. Answer any five questions of the following : 5 1=5

(a) N,N-diethyl-benzenesulphonamide is insoluble in alkali. Give reason.

(b) Aniline does not undergo Friedel-Crafts reaction. Why ?

56/1/1-11 23 P.T.O.

(J) _o{WbEo_rZ Am¡a Eo{ZbrZ _| {d^oX H$aZo Ho$ {bE gab amgm`{ZH$ narjU {b{IE &

(K) J¡{~«Eb W¡{b_mBS> g§íbofU _| gpå_{bV amgm`{ZH$ A{^{H«$`m {b{IE &

(L>) Amn Eo{ZbrZ H$m p-~«mo_moEo{ZbrZ _| ê$nmÝVaU H¡$go gånÞ H$a|Jo ?

(M) {ZåZ{b{IV A{^{H«$`m H$mo nyU© H$s{OE :

(N>) {ZåZ{b{IV A{^{H«$`m _| A Am¡a B H$s g§aMZmE± {b{IE :

NH3 Br2 + NaOH
A B

33. (H$) (i) {ZåZ{b{IV Ho$ H$maU {b{IE :

(1) Zn, Cd Am¡a Hg

2+
(2) Cr à~b AnMm`H$ h¡ O~{H$ Mn3+ à~b A
O~{H$ XmoZm| hr d4 ñnrerµO h¢ &
2+ o
(3) Cu /Cu H$m E _mZ + 0·34 V h¡ &

(ii) {ZåZ{b{IV amgm`{ZH$ g_rH$aU nyU© Am¡a g§Vw{bV H$s{OE :

(1) KMnO4
Ja_

+
(2) Cr2O72 + 6 I + 14 H 3+2=5

AWdm
56/1/1-11 24

(c) Write a simple chemical test to distinguish between methylamine
and aniline.

(d) Write the chemical reaction involved in Gabriel phthalimide
synthesis.

(e) How will you convert aniline to p-bromoaniline ?

(f) Complete the following reaction :

(g) Write the structures of A and B in the following reaction :

NH3 Br2 + NaOH
A B

33. (a) (i) Account for the following :

(1) The melting and boiling points of Zn, Cd and Hg are low.

4 2+
(2) Of the d species, Cr is strongly reducing while
3+
Mn is strongly oxidizing.
o 2+
(3) E value of Cu /Cu is + 0·34 V.

(ii) Complete and balance the following chemical equations :
heat
(1) KMnO4

+
(2) Cr2O72 + 6 I + 14 H 3+2=5

OR
56/1/1-11 25 P.T.O.

(I) (i) Cu2Cl2 Am¡a CuCl2 _| go H$m¡Z-gm Obr` {db`Z _| A{YH$ ñWm`r h¡
?

(ii) f- {dÝ`mg {b{IE &

(iii) {ZåZ{b{IV _| go H$m¡Z-gm ?
3+ 3+ 2+
Sc , Fe , Zn
[na_mUw H«$_m§H$ : Sc = 21, Fe = 26, Zn = 30]

(iv) Amn gmo{S>`_ H«$mo_oQ> go nmoQ>¡{e`_ S>mBH«$mo_oQ> H¡$go àmá H$a gH$Vo h¢ ?

(v) g§H«$_U YmVwE± ? 5 1=5

56/1/1-11 26

(b) (i) Out of Cu2Cl2 and CuCl2, which is more stable in aqueous
solution and why ?

(ii) Write the general electronic configuration of f-block
elements.

(iii) Predict which of the following will be coloured in aqueous
solution and why ?
3+ 3+ 2+
Sc , Fe , Zn
[Atomic number : Sc = 21, Fe = 26, Zn = 30]

(iv) How can you obtain potassium dichromate from sodium
chromate ?

(v) Why do transition metals and their compounds show
catalytic activities ? 5 1=5

56/1/1-11 27 P.T.O.

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