Tamil Nadu 11th Std Model Question Paper 2026 Chemistry

Tamil Nadu Board Model Question Paper

No. of Printed Pages : 11
8422
£vÄ Gs
A Register Number

!8422IstYearChemistry!
PART - III
÷Áv°¯À/CHEMISTRY
( uªÌ ©ØÖ® B[Q» ÁÈ / Tamil & English Version)

Põ» AÍÄ : 3.00 ©o ÷|µ® ] [ ö©õzu ©v¨ö£sPÒ : 70
Time Allowed : 3.00 Hours ] [Maximum Marks : 70

AÔÄøµPÒ : (1) AøÚzx ÂÚõUPЮ \›¯õP¨ £vÁõQ EÒÍuõ GߣuøÚ \›£õºzxU
öPõÒÍÄ®. Aa_¨£vÂÀ SøÓ°¸¨¤ß, AøÓU PsPõo¨£õÍ›h®
EhÚi¯õPz öu›ÂUPÄ®.
(2) }»® AÀ»x P¸¨¦ ø©°øÚ ©mk÷© GÊxÁuØS®
AiU÷PõikÁuØS® £¯ß£kzu ÷Ásk®. £h[PÒ ÁøµÁuØS
ö£ß]À £¯ß£kzuÄ®.
Instructions : (1) Check the question paper for fairness of printing. If there is any lack of fairness,
inform the Hall Supervisor immediately.
(2) Use Blue or Black ink to write and underline and pencil to draw diagrams.

SÔ¨¦ : ÷uøÁ¯õÚ ChzvÀ £h® Áøµ¢x \©ß£õkPøÍ GÊuÄ®.
Note : Draw diagrams and write equations wherever necessary.

£Sv & I / PART - I

SÔ¨¦ : (i) AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 15x1=15

(ii) öPõkUP¨£mkÒÍ |õßS ©õØÖ ÂøhPÎÀ ªPÄ® Hئøh¯
Âøhø¯z ÷uº¢öukzxU SÔ±mkhß Âøh°øÚ²® ÷\ºzx GÊuÄ®.
Note : (i) Answer all the questions.
(ii) Choose the most appropriate answer from the given four alternatives and write
the option code and the corresponding answer.

[ v¸¨¦P / Turn over

8422 2

1. ¤ßÁ¸ÁÚÁØÖÒ A¯Û¨ ¤øn¨¦, \P¨ ¤øn¨¦ ©ØÖ® DuÀ \P¨¤øn¨¦
Cøn¨¦PøÍ öPõskÒÍ ÷\º©® :
(A) NH3 (B) NaCl
(C) NH4Cl (D) CÁØÔÀ HxªÀø»
Among the following, the compound that contains, ionic, covalent and co-ordinate
linkage is :
(a) NH3 (b) NaCl
(c) NH4Cl (d) None of these

2. Gzv½iß S÷Íõøµøh }ºzu KOH Ehß ÂøÚ£kzx® ÷£õx ö£Ó¨£kÁx :
(A) £õº©õÀiøík (B) A]mhõÀiøík
(C) QøͯõU\õÀ (D) Gzv½ß QøÍUPõÀ
Ethylidene chloride on treatment with aqueous KOH gives :
(a) formaldehyde (b) acetaldehyde
(c) glyoxal (d) ethylene glycol

3. J¸ |À¼¯À¦ Áõ²Âß öÁ¨£{ø» ©ØÖ® PÚAÍÄ C¸ ©h[PõP AvP›US®
÷£õx Auß Bµ®£ AÊzu® P &°ß ©õØÓ® :
(A) P (B) 4 P (C) 3 P (D) 2 P
If Temperature and Volume of an ideal gas is increased to twice its values, the initial pressure
P becomes :
(a) P (b) 4P (c) 3P (d) 2P

4. Dz÷uÛß öÁÆ÷ÁÖ Á\ Aø©¨¦PÎß {ø»¨¦z ußø©°ß Á›ø\ :
(A) Gvöµvº > \õ´Ä > ©øÓzuÀ
(B) ©øÓzuÀ > \õ´Ä > Gvöµvº
(C) ©øÓzuÀ > Gvöµvº > \õ´Ä
(D) \õ´Ä > Gvöµvº > ©øÓzuÀ
The order of stabilities of various conformations of Ethane are :
(a) Staggered > Skew > Eclipsed
(b) Eclipsed > Skew > Staggered
(c) Eclipsed > Staggered > Skew
(d) Skew > Staggered > Eclipsed

A

3 8422

5. Á¼ø© ªS ªß£SίõÚ ÷£›¯® øímµõUø\iß }ºzu }ºUPøµ\¾US
ÁõsmíõL¨ Põµo (i) ©v¨¦ :
(A) 2 (B) 0 (C) 3 (D) 1
The Van’t Hoff Factor (i) for a dilute aqueous solution of the strong electrolyte
barium hydroxide is :

(a) 2 (b) 0 (c) 3 (d) 1

6. ö£ß÷\õ°U Aª»zvß G›uÀ öÁ¨£zvß ©v¨¦ :
(A) −7223 kJ mol−1 (B) −2237 kJ mol−1
(C) −2327 kJ mol−1 (D) −3227 kJ mol−1
The value of the heat of combustion for Benzoic acid is :

(a) −7223 kJ mol−1 (b) −2237 kJ mol−1

(c) −2327 kJ mol−1 (d) −3227 kJ mol−1

7. ÷\õi¯® GvÀ ÷\ªUP¨£kQÓx ?
(A) }º (B) ©sönsön´
(C) BÀPíõÀ (D) CÁØÔÀ HxªÀø»
Sodium is stored in :

(a) Water (b) Kerosene

(c) Alcohol (d) None of these

8. ¤ßÁ¸ÁÚÁØÖÒ Gx JÎ _ÇØÖ® £s¦øh¯x ?
(A) «÷\õ hõºhõ›U Aª»® (B) 3&S÷Íõ÷µõ ö£ß÷hß
(C) SÐU÷Põì (D) 2&S÷Íõ÷µõ ¦÷µõ¨÷£ß
Which of the following is optically active ?

(a) Meso-tartaric acid (b) 3-Chloropentane

(c) Glucose (d) 2-Chloro propane

A [ v¸¨¦P / Turn over

8422 4

9. ÷|ºSÔ G»Umµõß |õmh ©v¨¤øÚ ö£ØÖÒÍz uÛ©® :

(A) BºPõß (B) øímµáß (C) ¦Ñ›ß (D) ÷\õi¯®
The element with positive electron gain enthalpy is :

(a) Argon (b) Hydrogen (c) Fluorine (d) Sodium

10. Aq Gs 105 Eøh¯ AqÂÀ EÒÍ GzuøÚ G»UmµõßPÒ (n+l)=8 GßÓ
©v¨¤øÚ ö£Ó •i²® ?

(A) 15 (B) 30

(C) wº©õÛUP C¯»õx (D) 17
How many electrons in an atom with atomic number 105 can have value of (n+l)=8 ?

(a) 15 (b) 30

(c) Unpredictable (d) 17

11. ¤ßÁ¸ÁÚÁØÖÒ «÷\õö©›U ÂøÍÂØS Em£hõu ÷\º©® Gx ?

+
(A) C6H5NH2 (B) C6H5OH (C) C6 H5 N H3 (D) C6H5Cl

Which of the following species does not exert a resonance effect ?

+
(a) C6H5NH2 (b) C6H5OH (c) C6 H5 N H3 (d) C6H5Cl

12. ¤ßÁ¸ÁÚÁØÖÒ Gzv½ÛÀ (C2H4) Põn¨£k® Põº£ß \uÃuzvØS \©©õÚ
Põº£ß \uÃuzøu ö£ØÖÒÍx Gx ?

(A) ö£ß^ß (B) ¦µ¨¥ß (C) Dz÷uß (D) Dzøuß
Which of the following compound has the same percentage of Carbon as in Ethylene (C2H4) ?

(a) Benzene (b) Propene (c) Ethane (d) Ethyne

A

5 8422

13. K÷\õß £h» ]øuÄ E¸ÁõUSÁx :
(A) E°º ö£¸UP® (B) Põmkz w
(C) E»P öÁ¨£©¯©õuÀ (D) yº¢x÷£õuÀ
Ozone depletion will cause :
(a) bio-magnification (b) forest fires
(c) global warming (d) eutrophication

14. N2 + 3H2 ⇌ 2 NH3 GßÓ ÂøÚ°ß KC = ?
(g) (g) (g) KP

1
(A) RT (B) RT (C) (RT)2 (D) RT

KC
for the reaction,
KP
N2 + 3H2 ⇌ 2 NH3 is :
(g) (g) (g)

1
(a) RT (b) (c) (RT)2 (d) RT
RT

15. TØÖ : PiÚ }øµ \»øÁa ÷\õhõÄhß ÂøÚ¨£kzxÁuß ‰»®, Auß
{µ¢uµU PiÚz ußø©°øÚ }UP»õ®.
Põµn® : \»øÁ ÷\õhõ, PiÚ }›À Pøµ¢xÒÍ PõÀ]¯®, ö©UÜ]¯®
S÷Íõøµk ©ØÖ® \À÷£mPÐhß ÂøÚ¦›¢x Pøµ¯õu
Põº£÷ÚmkPøÍ E¸ÁõUSQÓx.
(A) TØÖ \›¯õÚx, BÚõÀ Põµn® uÁÓõÚx.
(B) TØÖ ©ØÖ® Põµn® Cµsk® \›, ©ØÖ® Põµn®, TØÖUS \›¯õÚ
ÂÍUP©õS®.
(C) TØÖ ©ØÖ® Põµn® Cµsk® uÁÖ.
(D) TØÖ ©ØÖ® Põµn® Cµsk® \›, BÚõÀ Põµn®, TØÔØS \›¯õÚ
ÂÍUP©À».
Assertion : Permanent hardness of water is removed by treatment with Washing soda.
Reason : Washing soda reacts with soluble Calcium and Magnesium chlorides and
sulphates in hard water to form insoluble carbonates.
(a) Assertion is true but Reason is false.
(b) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(c) Both Assertion and Reason are false.
(d) Both Assertion and Reason are true but Reason is not the correct explanation of
Assertion.

A [ v¸¨¦P / Turn over

8422 6

£Sv & I I / PART - II
SÔ¨¦ : GøÁ÷¯Ý® BÖ ÂÚõUPÐUS Âøh¯ÎUPÄ®. ÂÚõ Gs 24 &US
Pmhõ¯©õP Âøh¯ÎUPÄ®. 6x2=12

Note : Answer any six questions. Question No. 24 is compulsory.

16. J¨¦ Aq {øÓ – Áøµ¯ÖUPÄ®.
Define Relative Atomic Mass.

17. öí´\ߣºUQß {a\¯©ØÓ ußø© ÷Põm£õmøhU TÖP.
State Heisenberg’s Uncertainty principle.

18. ‰ßÖ ÁøP¯õÚ \P¨¤øn¨¦ øímøµkPøÍU SÔ¨¤kP.
Name the three types of covalent Hydrides.

19. J¸ Áõ²Âß PÚAÍÄ ©ØÖ® ÷©õÀPøÍ öuõhº¦£kzx® Pou•øÓ
Áõ´£õmiøÚz u¸P.
Give the Mathematical expression that relates gas volume and moles.

20. öÁ¨£ C¯UP¯¼ß ‰ßÓõ® Âvø¯ TÖP.
State the Third law of Thermodynamics.

21. £u[P©õuÀ GßÓõÀ GßÚ ?
What is Sublimation ?

22. yshÀ ÂøÍÄ GßÓõÀ GßÚ ?
What is Inductive effect ?

23. £Û¨¦øP – Áøµ¯ÖUPÄ®.
Define Smog.

A

7 8422

24. NH 3, N 2 ©ØÖ® H2 BQ¯ÁØÔß \© {ø»a ö\ÔÄPÒ •øÓ÷¯ 1.8×10−2 M,
1.2×10−2 M ©ØÖ® 3×10−2 M. N2 ©ØÖ® H2 &¼¸¢x NH3 E¸ÁõS® ÂøÚUS
\© {ø» ©õÔ¼°ß ©v¨¤øÚU PõsP.
The equilibrium concentrations of NH 3, N2 and H2 are 1.8×10−2 M, 1.2×10−2 M and
3×10−2 M respectively. Calculate the equilibrium constant for the formation of NH3 from
N2 and H2.

£Sv & II I / PART - III
SÔ¨¦ : GøÁ÷¯Ý® BÖ ÂÚõUPÐUS Âøh¯ÎUPÄ®. ÂÚõ Gs 33 &US
Pmhõ¯©õP Âøh¯ÎUPÄ®. 6x3=18

Note : Answer any six questions. Question No. 33 is compulsory.

25. ¤ßÁ¸ÁÚÁØÔß J¨¦ ‰»UTÖ {øÓ°øÚU PnUQkP.
(i) GzuÚõÀ (C2H5OH)
.
(ii) SÐU÷Põì (C6H12O6)
Calculate the relative molecular mass of the following.
(i) Ethanol (C2H5OH)
(ii) Glucose (C6H12O6)

26. G»Umµõß PÁºußø©UPõÚ £õ¼[ •øÓ°ß Ai¨£øhø¯ _¸UP©õP uµÄ®.
Briefly give the basis for Pauling’s Scale of electronegativity.

27. £õµõ øímµáøÚ, Bºz÷uõ øímµáÚõP GÆÁõÖ ©õØÖÁõ´ ?
How do you convert para hydrogen into ortho hydrogen ?

28. a=0 GßÓ Áõshº ÁõÀì ©õÔ¼ø¯U öPõsh Áõ²ÂøÚ vµÁ©õUP •i²©õ ?
ÂÁ›.
Can a gas with Vander Waals constant a=0 be liquefied ? Explain.

29. öíßÔ Âv°ß Áµ®¦PÒ ¯õøÁ ?
What are the limitations of Henry’s law ?

A [ v¸¨¦P / Turn over

8422 8

30. A¯Û¨¤øn¨¤¾ÒÍ \P¨¤øn¨¦z ußø©ø¯ ÂÍUSP.
Explain the covalent character in ionic bond.

31. ©õØÔ¯® (Isomerism) GßÓõÀ GßÚ ? Auß ÁøPPøÍU TÖP.
What is Isomerism ? Give its types.

32. S÷Íõ÷µõ ö£ß^Ûß £¯ßPÒ ¯õøÁ ?
What are the uses of Chlorobenzene ?

33. J롧 •ßÛø»°À «z÷uß ©ØÖ® S÷Íõ›ß Cøh÷¯ {PÊ® \[Q¼
ÂøÚUPõÚ \©ß£õkPøÍ GÊxP.
Write the equations for the chain reaction between Methane and Chlorine in the presence of
light.

£Sv & IV / PART - IV
SÔ¨¦ : AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 5x5=25

Note : Answer all the questions.

34. (A) (i) ÷©õ»õº PÚ AÍÄ – Áøµ¯Ö.
(ii) ÷£õº Aq ©õv›°ß Áµ®¦PÒ ¯õøÁ ?
AÀ»x
(B) (i) ÷í»áßPÒ BUêá÷ÚØÔ¯õP ö\¯À£kÁx Hß ?
(ii) öuõSvPÒ ©ØÖ® Á›ø\PÎÀ G»Umµõß PÁºußø©°À HØ£k®
BÁºzuÚ ©õØÓ[PøÍU TÖP.
(a) (i) Define Molar Volume.
(ii) What are the limitations of Bohr’s atom model ?
OR
(b) (i) Why halogens act as oxidising agents ?
(ii) State the trends in the periodic variations of electronegativity in Groups and Periods.

A

9 8422

35. (A) PõÀ]¯® ©ØÖ® ö©UÜ]¯zvß E°›¯À •UQ¯zxÁzøu ÂÁ›.
AÀ»x
(B) ÷\õi¯® S÷Íõøµk £iPzvß £iPU Tk BØÓø» PnUQk® ©øÓ•P
•øÓø¯ ÂÍUSP.
(a) Describe briefly the biological importance of Calcium and Magnesium.

OR

(b) Explain an indirect method to calculate lattice enthalpy of Sodium chloride crystal.

36. (A) ½ \õm¼¯º öPõÒøP°øÚ¨ £¯ß£kzv \©{ø»°ß «x RÌPsh
PõµoPÒ HØ£kzx® ©õØÓzøu ÂÍUSP.
(i) ö\ÔÄ
(ii) AÊzu®
(iii) öÁ¨£{ø»
(iv) ÂøÚ÷ÁP ©õØÔ
(v) ©¢u Áõ²
AÀ»x
(B) öµÍÀm Âvø¯¨ £¯ß£kzv vµÁzvÀ vµÁzøuU öPõsh C¸ TÖ
Pøµ\¼ß B AÊzuzvØPõÚ \©ß£õmøh Á¸Â.
(a) Using Le-Chatelier’s principle explain the effect of the following factors on equilibrium.

(i) Concentration

(ii) Pressure

(iii) Temperature

(iv) Catalyst

(v) Inert gas

OR

(b) Derive the expression for vapour pressure of binary solution of liquid in liquids using
Raoult’s law.

A [ v¸¨¦P / Turn over

8422 10

37. (A) O2 ‰»UTÖ E¸Áõuø» ‰»UTÖ Bº¨¤mhõÀ (MO) öPõÒøP ‰»®
£hzxhß ÂÍUPÄ®.
AÀ»x
(B) (i) ¤ßÁ¸® ÷\º©[PÐUS IUPAC •øÓ°À ö£¯›kP.
(I)

(II)

(ii) A ©ØÖ® B &ø¯ Psk¤i.

(I)

(II)

(a) Discuss the formation of O2 molecule using Molecular Orbital (MO) theory with diagram.
OR
(b) (i) Give the IUPAC names of the following compounds.
(I)

(II)

(ii) Identify ‘A’ and ‘B’.

(I)

(II)

A

11 8422

38. (A) ö£ß^øÚ RÌPsh ÷\º©[PÍõP GÆÁõÖ ©õØÖÁõ´ ?
(i) S÷Íõ÷µõ ö£ß^ß
(ii) Áøͯ öíU÷\ß
(iii) ö©¼°U Aª»®
AÀ»x
(B) ¤ßÁ¸ÁÚ £ØÔ ]Ö SÔ¨¦ ÁøµP.
(i) µõè •øÓ
(ii) öhÍ •øÓ
(iii) ÂÀ¼¯®\Ûß Duº öuõS¨¦
(a) How will you convert Benzene to the following compounds ?
(i) Chloro benzene
(ii) Cyclohexane
(iii) Maleic acid
OR
(b) Write short notes on the following.
(i) Raschig process
(ii) Dow’s process
(iii) Williamson’s Ether synthesis

-oOo-

A [ v¸¨¦P / Turn over