TN 12th Question Paper 2025 Chemistry

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8322
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!8322Chemistry!
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¢öukzx 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 corresponding answer.

[ v¸¨¦P / Turn over

8322 2

1. H2O 2 ]øuÁøh¢x O 2 &øÁz u¸® ÂøÚ°À J¸ SÔ¨¤mh ÷|µzvÀ J¸
{ªhzvØS 48 g O2 E¸ÁõÚõÀ AUSÔ¨¤mh ÷|µzvÀ }›ß E¸ÁõuÀ ÷ÁP® :
(A) 2.25 mol min−1 (B) 0.75 mol min−1
(C) 3.0 mol min−1 (D) 1.5 mol min−1
During the decomposition of H2O2 to give dioxygen, 48 g O2 is formed per minute at certain
point of time. The rate of formation of water at this point is :

(a) 2.25 mol min−1 (b) 0.75 mol min−1

(c) 3.0 mol min−1 (d) 1.5 mol min−1

2. 1 ÷©õÀ ö£õmhõ]¯® øhS÷µõ÷©m BÚx ö£õmhõ]¯® A÷¯õøhkhß
ÂøÚ£mk öÁÎ÷¯ØÖ® A÷¯õiß ÷©õÀPÎß GsoUøP ?
(A) 3 (B) 1 (C) 4 (D) 2
How many moles of I2 are liberated when 1 mole of potassium dichromate react with potassium
iodide ?

(a) 3 (b) 1 (c) 4 (d) 2

3. ö£õxÁõP, Jmhõ \ø©¯À £õzvµ[PÎß ÷©Ø£µ¨¤À £»£i §\¨£mkÒÍx.
A¢u £»£i°ß JØøÓ¨£i ‰»UTÖ :
(A) S÷Íõ÷µõDzwß
(B) Dz÷uß
(C) 1,1,2,2&öhmµõL¦Ñ÷µõDz÷uß
(D) ¦µ¨&2&Dßø|møµÀ
Non-stick cookwares generally have a coating of a polymer, whose monomer is :

(a) chloroethene

(b) ethane

(c) 1,1,2,2-tetrafluoroethane

(d) prop-2-enenitrile

A

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4. ø|mµì Aª»zxhß ÂøÚ¦›¢x ©g\Ò {Ó Gsön´ ÷£õßÓ }º©zøuz
u¸Áx __________.
(A) N&ö©zvÀ AÛ½ß (B) ø|m÷µõ ö£ß^ß
(C) N,N&øhö©zvÀ AÛ½ß (D) AÛ½ß
The compound that reacts with nitrous acid to give yellow oily liquid is __________.
(a) N-methylaniline (b) Nitro benzene
(c) N,N-dimethyl aniline (d) Aniline

5. ÷£õ›U Aª»® J¸ Aª»©õS®. HöÚÛÀ Auß ‰»UTÖ :
(A) ¦÷µõmhõÝhß Cøn¢x }º ‰»UTÔøÚz u¸QÓx.
(B) Ch¨ö£¯ºa] Aøh²® ußø©²øh¯ H+ A¯Ûø¯U öPõskÒÍx.
(C) }º ‰»UTÔ¼¸¢x OH− A¯Ûø¯ HØÖU öPõsk ¦÷µõmhõøÚz u¸QÓx.
(D) ¦÷µõmhõøÚz uµÁÀ»x.
Boric acid is an acid because its molecule :
(a) combines with proton to form water molecule.
(b) contains replaceable H+ ion.
(c) accepts OH− from water, releasing proton.
(d) gives up a proton.

6. ªß¦»zvÀ øÁUP¨£mkÒÍ J¸ TÌ©{ø» Aø©¨¤À EÒÍ xPÒPÒ
Gvºªß•øÚø¯ ÷|õUQ |P¸QßÓÚ. A÷u TÌ©UPøµ\¼ß v›uÀ {PÌÁõÚx
(i) K2SO4, (ii) Na3PO4, (iii) K4[Fe(CN)6] ©ØÖ® (iv) NaCl BQ¯ÁØøÓU öPõsk
B´Ä ö\´¯¨£kQßÓx. AÁØÔß ÃÌ£iÁõS® vÓß
(A) (iii) > (ii) > (i) > (iv) (B) (i) > (ii) > (iii) > (iv)
(C) (ii) > (i) > (iv) > (iii) (D) CÁØÔÀ GxĪÀø»
In an electrical field, the particles of a Colloidal system move towards cathode. The
coagulation of the same sol is studied using (i) K2SO4, (ii) Na3PO4, (iii) K4[Fe(CN)6] and
(iv) NaCl. Their coagulating power should be :
(a) (iii) > (ii) > (i) > (iv) (b) (i) > (ii) > (iii) > (iv)
(c) (ii) > (i) > (iv) > (iii) (d) None of these

A [ v¸¨¦P / Turn over

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7. TØÖ :S÷Íõ›ß Áõ²øÁU Põmi¾® L¦Ñ›Ûß ¤øn¨¦ ¤ÍÄ
BØÓÀ AvP®.
Põµn® : S÷Íõ›ÚõÚx, L¦Ñ›øÚU Põmi¾® AvP G»Umµõß Â»US
Âø\°øÚ ö£ØÖÒÍx.
(A) TØÖ \› BÚõÀ Põµn® uÁÖ.
(B) TØÖ ©ØÖ® Põµn® Cµsk® \›, ÷©¾® Põµn©õÚx TØÔØS \›¯õÚ
ÂÍUP©õS®.
(C) TØÖ ©ØÖ® Põµn® Cµsk® uÁÖ.
(D) TØÖ ©ØÖ® Põµn® Cµsk® \›, BÚõÀ Põµn©õÚx TØÔØS \›¯õÚ
ÂÍUP©À».
Assertion : Bond dissociation energy of Fluorine is greater than Chlorine gas.
Reason : Chlorine has more electronic repulsion than Fluorine.
(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.

8. L¦Ñøµm ÁiÁø©¨ø£¨ ö£ØÖÒÍ PõÀ]¯® L¦ÑøµiÀ Põn¨£k®
Ca2+ ©ØÖ® F− A¯ÛPÎß AønÄ GsPÒ •øÓ÷¯ :
(A) 8 ©ØÖ® 4 (B) 4 ©ØÖ® 2 (C) 4 ©ØÖ® 8 (D) 6 ©ØÖ® 6
In calcium fluoride, having the flurite structure, the coordination number of Ca2+ ion and
F− ion are :
(a) 8 and 4 (b) 4 and 2 (c) 4 and 8 (d) 6 and 6

9. ¦µuzvß Cµshõ® {ø» Aø©¨£õÚx GøuU SÔUQßÓx ?
(A) α&Aª÷Úõ Aª»[PÎß Á›ø\
(B) £õ¼ö£¨øhk •xöP¾®¤ß {ø»¯õÚ Á\Aø©¨¦
(C) α&_¸Ò •xöP¾®¦
(D) }ºöÁÖUS® Cøh±kPÒ
The secondary structure of a protein refers to _________.
(a) sequence of α-amino acids
(b) fixed configuration of the polypeptide backbone
(c) α-helical backbone
(d) hydrophobic interaction

A

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10. }›ß A¯Û¨ ö£¸UP ©õÔ¼ Kw &Cß ©v¨¦ 258C öÁ¨£{ø»°À 1.00×10−14
GÛÀ, 408C öÁ¨£{ø»°À Auß ©v¨¦ __________.
(A) 1.00×10−14 (B) 1.14×10−15
(C) 2.71×10−14 (D) 2.95×10−15
At 258C, ionic product constant Kw of water is 1.00×10−14. Its value at 408C is __________.

(a) 1.00×10 −14 (b) 1.14×10 −15

(c) 2.71×10 −14 (d) 2.95×10 −15

11. [Pt(NO2)(H2O)(NH3)2]Br GßÓ AønÂÀ ø©¯ E÷»õP A¯Û°ß BU]á÷ÚØÓ
Gs GßÚ ?
(A) +4 (B) +2 (C) +6 (D) +3
What is the oxidation number of the central metal ion in the complex,

[Pt(NO2)(H2O)(NH3)2]Br ?

(a) +4 (b) +2 (c) +6 (d) +3

12. ö©õzu©õP 9650 T¿®PÒ ªßÞmhzøu ö£ØÖÒÍ G»UmµõßPÎß GsoUøP :
(A) 6.022×10 22 (B) 6.22×1023 (C) 6.022×10−34 (D) 6.022×10 24
The number of electrons that have a total charge of 9650 coulombs is :

(a) 6.022×10 22 (b) 6.22×10 23 (c) 6.022×10 −34 (d) 6.022×10 24

13. ¤ßÁ¸ÁÚÁØÖÒ Gx Á¼ø© ªUP Aª»® ?
(A) 4-ø|m÷µõ¥ÚõÀ (B) 2-ø|m÷µõ¥ÚõÀ
(C) 3-ø|m÷µõ¥ÚõÀ (D) 4-S÷Íõ÷µõ¥ÚõÀ
Which one of the following is the Strongest acid ?

(a) 4-nitrophenol (b) 2-nitrophenol

(c) 3-nitrophenol (d) 4-chlorophenol

A [ v¸¨¦P / Turn over

8322 6

14. KCN 3 H O+5 → (C) PCl
CH3 Br → (A) → (B) 
Âøͨ ö£õ¸Ò (C) Gߣx :
(A) S÷Íõ÷µõ A]miU Aª»®
(B) α&S÷Íõ÷µõ \¯÷Úõ GzuÚõ°U Aª»®
(C) A]møhÀ S÷Íõøµk
(D) CÁØÔÀ HxªÀø»
KCN 3 H O+5 → (C) PCl
CH3 Br → (A) → (B) 
Product (C) is :
(a) chloro acetic acid
(b) α-chlorocyano ethanoic acid
(c) acetylchloride
(d) none of these

15. ]ÀÁº ©ØÖ® u[P® ¤›zöukzuÀ •øÓ¯õÚx \¯øÚøhU öPõsk PÊÄuø»
EÒÍhUQ¯x. C®•øÓ°À ¤ßÚº ]ÀÁº «Í¨ ö£Ó¨£kuÀ :
(A) xzu|õPzxhß E÷»õP Ch¨ö£¯ºa] ÂøÚ
(B) Áõø» ÁizuÀ
(C) }º©©õUPÀ
(D) ¦» y´ø©¯õUPÀ
Extraction of gold and silver involves leaching with cyanide ion. Silver is later recovered by :
(a) Displacement with Zinc
(b) Distillation
(c) Liquation
(d) Zone refining

£Sv & II / 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. GÆÁøP uõxUPøÍ Ahº¨¤UP ~øµ ªu¨¦ •øÓ HØÓx ? AzuøP¯
uõxUPÐUS Kº GkzxUPõmk u¸P.
Which type of ores can be concentrated by froth floatation method ? Give an example for ores.

17. PCl5 &I öÁ¨£¨£kzx® ÷£õx {PÌÁx ¯õx ?
What happens when PCl5 is heated ?

A

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18. ]º÷PõÛ¯® ©ØÖ® íõ¨Û¯® Jzu¨ £s¦Pøͨ ö£ØÖÒÍÚ. Hß ?
Why do Zirconium and Hafnium exhibit similar properties ?

19. PøµvÓß ö£¸UP® – Áøµ¯ÖUPÄ®.
Define Solubility Product.

20. "\©õÚ PhzxzvÓß' – Áøµ¯ÖUPÄ®.
Define Equivalent Conductance.

21. ÃÌ£iøÁ TÌ©U Pøµ\»õP ©õØÖÁuØPõP TÌ©©õUQ ÷\ºUP¨£kQÓx.
CUTØøÓ GkzxUPõmkhß ÂÍUSP.
Peptising agent is added to convert precipitate into colloidal solution. Explain this statement
with an example.

22. Põmhº©õß & Ta ÂøÚø¯ GÊxP.
Write Gattermann - Koch reaction.

23. ©¸¢x¨ ö£õ¸mPÒ GÆÁõÖ ÁøP¨£kzu¨£kQßÓÚ ?
How are drugs classified ?

24. ¤ßÁ¸® ÂøÚPÎÀ ÂøÚ Âøͨ ö£õ¸mPÒ X ©ØÖ® Y &ø¯U PshÔP.

Find the products X and Y in the following reactions.

A [ v¸¨¦P / Turn over

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£Sv & III / 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. {UPø»z y´ø©¯õUP¨ £¯ß£k® J¸ •øÓ°øÚ ÂÁ›UPÄ®.
Describe a method for refining Nickel.

26. P¢uP øhBUø\iß öÁÐUS® £s¤øÚ¨ £ØÔ ]Ö SÔ¨¦ ÁøµP.
Write short notes on bleaching action of Sulphur dioxide.

27. }÷µØÓ ©õØÔ¯[PÒ GßÓõÀ GßÚ ? J¸ Euõµnzxhß ÂÍUSP.
What are hydrate isomers ? Explain with an example.

28. |õß•Q ©ØÖ® Gs•Q öÁØÔh[PøÍ ÷ÁÖ£kzxP.
Distinguish tetrahedral and octahedral voids.

29. L¤µsm¼a £µ¨¦ PÁºuÀ \©öÁ¨£U ÷PõmiØPõÚ Áµ®¦PÒ ¯õøÁ ?
What are the limitations of Freundlich adsorption isotherm ?

30. ¤ßÁ¸® ÂøÚÁ›ø\°À EÒÍ A, B ©ØÖ® C BQ¯ ÷\º©[PøÍ PshÔP.

Identify compounds A, B and C in the following sequence of reaction.

A

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31. SÖUP £»£i GßÓõÀ GßÚ ? Cµsk GkzxUPõmkPÒ u¸P.
What is Condensation Polymer ? Give two examples.

32. E°›Ú[PÎÀ ¼¨¤kPÎß H÷uÝ® ‰ßÖ ö\¯À£õkPøÍ SÔ¨¤kP.
Mention any three functions of lipids in living organism.

33. J¸ •uÀ ÁøP ÂøÚ°ß ÂøÚ÷ÁP ©õÔ¼ 1.54×10−3 s−1. Auß Aøµ ÁõÌ
Põ»zvøÚ PshÔP.
The rate constant for a first order reaction is 1.54×10−3 s−1. Calculate its half life time.

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

Note : Answer all the questions.

34. (A) (i) ¤ßÁ¸® ö\¯À•øÓPÎÀ öPõkUP¨£mkÒÍÁØÔß £¯ß£õmiøÚ
ÂÁ›UP.
(1) A¾ªÛ¯® ¤›zöukzu¼À Qøµ÷¯õø»m
(2) ]º÷PõÛ¯zvß «y´ø©¯õUP¼À A÷¯õiß
(ii) ÷í»áß Cøha ÷\º©[PÎß H÷uÝ® ‰ßÖ £s¦PøÍU TÖP.
AÀ»x
(B) (i) ÷£õ÷µm EÖ¨ø£ GÆÁõÖ PshÔÁõ´ ?
(ii) ÷£õµõUì &ß £¯ßPøÍz u¸P.
(a) (i) Describe the role of the following in the process mentioned.

(1) Cryolite in the extraction of Aluminium.

(2) Iodine in the refining of Zirconium.

(ii) State any three properties of inter halogen compounds.

OR

(b) (i) How will you identify borate radical ?

(ii) Give the uses of Borax.

A [ v¸¨¦P / Turn over

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35. (A) ö£õmhõ]¯® øhS÷µõ÷©m u¯õ›zuø» ÂÍUSP.
AÀ»x
(B) öÁºÚº öPõÒøP°ß ÷Põm£õkPøÍU TÖP.
(a) Describe the preparation of potassium dichromate.
OR
(b) Write the postulates of Werner’s theory.

36. (A) (i) E÷»õP® AvP•ÒÍ SøÓ£õmiøÚ J¸ GkzxUPõmkhß ÂÍUSP.
(ii) ÷£õ¼ •uÀ ÁøP ÂøÚø¯ J¸ GkzxUPõmkhß ÂÍUSP.
AÀ»x
(B) 0.1 M CH3COOH Pøµ\¼ß pH ©v¨ø£ PnUQkP. A]miU Aª»zvß
¤›øP ©õÔ¼ ©v¨¦ 1.8×10−5.
(a) (i) Write a short note on metal excess defect with an example.
(ii) Explain Pseudo first order reaction with an example.
OR
(b) Calculate the pH of 0.1 M CH3COOH solution. Dissociation constant of acetic acid
is 1.8×10−5.

37. (A) ö|ºßìm \©ß£õmøhz u¸Â.
AÀ»x
(B) RÌPsh ©õØÓ[PøÍ GÆÁõÖ {PÌzxÁõ´ ?
(i) GzvÀ BÀPíõÀ → Dzwß
(ii) Gzv½ß QøÍUPõÀ → 1,4-øhBU÷\ß
(iii) QÎ\µõÀ → AU÷µõ¼ß
(a) Derive an expression for Nernst equation.
OR
(b) How will you convert
(i) Ethyl alcohol → Ethene
(ii) Ethylene glycol → 1,4-dioxane
(iii) Glycerol → Acrolein

A

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38. (A) C7H6O GßÓ ‰»UTÖ Áõ´£õk öPõsh P›©a ÷\º©® (A) BÚx PõßÛ\÷µõ
ÂøÚUS Em£kQßÓx. ÷\º©® (A) BÚx, Ahº FeCl 3 •ßÛø»°À
S÷Íõ›ß Ehß ÂøÚ¦›¢x ÷\º©® (B) &ø¯z u¸QÓx. ÷©¾® ÷\º©®
(A) BÚx, ÂøÚ÷ÁP ©õØÔ CÀ»õu ö£õÊx S÷Íõ›ß Ehß ÂøÚ¦›¢x
÷\º©® (C) &ø¯z u¸QÓx. A, B ©ØÖ® C BQ¯ÁØøÓ PshÔ¢x uS¢u
ÂøÚPøÍz u¸P.
AÀ»x
(B) (i) &Cß ø|m÷µõ ©ØÖ® A] ÁiÁ[PøÍ GÆÁõÖ
CH 3 NO 2
÷ÁÖ£kzxÁõ´ ?
(ii) ö\À¼À Põn¨£k® RNA &Âß ÁøPPÒ ¯õøÁ ?
(a) An organic compound (A) of molecular formula C7H6O undergoes Cannizaro reaction.
Compound (A) also reacts with Chlorine in the presence of Conc.FeCl 3 to give
Compound (B). Compound (A) reacts with Chlorine in the absence of catalyst to give
Compound (C). Identify A, B and C with suitable reactions.

OR

(b) (i) How will you distinguish between nitro and aci form of CH3NO2 ?

(ii) What are the types of RNA which are found in cell ?

-oOo-

A [ v¸¨¦P / Turn over

Study Materials
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Model Papers Class 6 Notes

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Class 9 Notes
Important Resources
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Periodic Table
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