Karnataka 2PUC Preparatory Exam Question Paper 2025 Chemistry

DISTRICT LEVEL IIPUC PREPARATORY EXAM, JANUARY 2025
Time: 3 Hours Max. Marks: 70
Sub:CHEMISTRY (34)
General Instructions:
1. The question paper has five parts
2. (a) Part - A carries 20 marks, eachhaving 46. All parts are compuisory.
question carries 1mark.
(b) Part-Bcarries 06 marks, each question
carries 2marks.
(c) Part-Ccarries 15 marks, each question carries
(d) Part-D carries 20 marks,each guestion carries 35 marks.
marks.
(e) Part-E carries 09 marks, each guestion (probem) carries
3. In Part - Aquestion,first attempted answer will be considered for3marks.
4. Write balanced chemical equations and draw awarding marks.
diagrams wherever necessary.
2Direct answers to the numerical problems without detaledsteps and specific unit for final answer will not carry any marks
6. Use log table and simple calculators if necessary. (Use of scientific calculator is not allowed).
PART -A
I. Select the correct option from the given choices: 15 x 1= 15
1. Which of the following is dependent on
(A) Molaríty temperature? (B) Mole fraction
(C) Weight percentage (D) Molality
2. For .1M solution, the colligative property willfollow the order
(A) NaCl > Na,SO, > Na,PO, (B) NaCl< Na, S0, < Na,PO4
(c) NaCl <Na,SO, Na,PO4 (D) NaCl < Na,SO, = Na,PO,
3. For a zero order reaction, the intercept for the plot of concentration of reactants Vs time is equal
to
(A) -k (B) log k (c) [R,] (D) log [R,]
4. Statement 1: Fe ions show paramagnetic and magnetic moment of 5.92BM
Statement 2: Fe jons have d electronic configuration.
ldentify the correct statement.
(A)Statement 1is incorrect and Statement 2 is correct
(B) Both Statements 1and 2 are incorrect
(C) Both Statement 1and 2 are correct
(D) Statement 1 is incorrect and Statement 2 is incorrect

5. The primary and secondary valencies of | Fe( C,0,). complexes are
(A) 3 and 3 (B) 3and 6 (C) 6 and 3 (D) 0 and 3
6. Statement 1: The crystal field theory (CFT) is an
metalHigand bond-to be ionic.
electrostatic model which considers the
Statement 2: The crystal field theory (CFT) considers ligands as point dipoles incase of
molecules. neutral
ldentify the correct statement.
(A)Both Statement 1 and 2 are correct
(B) Both Statements 1 and 2 are incorrect
(C) Statement 1is incorrect and Statement 2 is incorrect
(D)Statement 1 is incorrect and Statement 2 is correct
7. The best reagent used to produce pure alkyl halides from alcohol is
(A)Concentrated HCI (B) Concentrated HBr (C) SOCI, (D) NaBr
1

8. Select the incorrect match.
(A) Swartz reaction-CoF, (B) Finkelstein reaction - al
(C) Sandmeyers reaction - CuCl, (D) Wurtz reaction - Nal dry ether
9. ldentify the simple ether from the following
(A) CH,0C,H, (B) CH,0C,H, (C) CH,0C,H, (D) CGH,OCH,
10.Which of the following compound can convert phenol to benzene?
(A) CrO, (B) Zinc dust (C) Pyridine (D) Strong acid
11.Which of the following carbonyl compounds can be prepared from Rosenmund reaction?
(A)Methanal (B) Acetone (C) Butanone (D) Benzaldehyde
12.A compound on treatment with hydrazine followed by heating upto 473K with KOH in ethylene
glycol gives propane. ldentify the compound.
(A) Methanal (B) Ethanal (C) Propanal (D) Acetone
13.Which of the following is a 2' amine?
(A) CH,CH,NHCH, (B) (CH,), N
(C) (CH,CH,CH,), NCH, (D)CH,NH,
14.Which of the following is a non -reducing sugar?
(A) Galactose (B) Glucose (C) Fructose (D) Sucrose
15.Which of the following amino acids are aromatic in nature?
(A)Methionine (B) lsoleucine (C) Proline (D) Histidine
II. Fill in the blanks choosing the appropriate word from those given in the brackets: 5 x 1= 5
3
(Chromium, sp, sp', Hoffnmann, Galvanisation, Reverse osmosis)
16. Desalination of water is based on
17. Protection of iron by coating with zinc is called
18. Element with more unpaired electron in 3d series is
19. In Allylic alcohols - OH group is attached to a hybridized carbon adjacent to the
carbon-carbon double bond.
20. developed a method for preparation of primary amines by treating an amide with
bromine in aqueous or ethanolic solution of sodium hydroxide.

PART -B
II. Answer any THREE of the following questions. Each question carries TWO marks: 3x 2 6
21. According to the collision theory give any two criteia for effective colisaion.
22. Why is Cr* reducing and Mn* oxidizing when both have dconfiguration.
23. Complete the following reactions:
(a) CH,MgBr + C,H,ONa -’
(b) CH,Br+ KNO, -’

24. ldentify the major product formed in the following reaction. Write its IUPAC name.
CH, -CH= CH, H,0 H* ’ ?
25. Write the HawWorth structure of Sucrose.
PART -C
V. Answer any THREE of the following. Each question carries THREE marks: 3x3=9
26. Write the balanced chemical equations for the reactions involved in preparation of
potassium dichromate from Chromite ore. [3M]
27. (a) Write any two differences between Lanthanoids and Actinoids? (2M]
(b) What is the composition of Mischmetal? [1M]
28. On the basis of Valence Bond Theory (VBT) explain the hybridization, geometrical
[3M]
shape and magnetic property of|Ni(CN), complex.
29. Write any three postulates of Werner's theory of complexes. [3M]
[2M]
30. (a)Write the structures of geometrical isomers of Co(NH,). (NO,),
(b) Write thelUPAC name of Co(NH,), (H,0), |C,
V. Answer any TWO of the following. Each question carries THREE marks: 2x3= 6
31. Give any three differences between solutions showing positive and negative deviation from
ideal behaviour.

32. Describe the construction and working of SHE or Standard Hydrogen Electrode.
33. Writea neat diagram of H, -0, Fuel cell and express its cathodic and anodic reactions.
34. Derive the integrated rate equation for first order reaction.
PART -D
VI. Answer any FOUR of the following. Each question carries FIVE marks: 4x 5 =20

35. (a) Wite the steps involved in mechanism of conversion of 2-bromo-2-methyl butane
into 2-methyl-butan-2-ol. Which type of solvent favors such reaction? [3M]
(b) Define the following: () Racemic mixtures (ii) Enantiomers. (2M]

36. (a) Write the mechanism of acid catalysed dehydration of ethanol to ethene. [3M]
(b)Explain Kolbe's reaction with an example. [2M]
37. (a) Explain the preparation of carboxylic acids from Grignard reaget. Give equation. [3M]
(b) Explain HVZ (Hell - Volhard-Zelinsky) reaction with example. [2M]
derivatives to
38. (a) Write the general equation involved in addition of ammonia and its
carbonyl group. [2M]
(b) Explain Cannizzaro's reaction with an example.
[2M]
more acidic? [1M]
(c) Among methanoic acid and ethanoic acid, which is

3 P.T.0.

39. (a) Write the general equation involved in Gabriel phthalimide synthesis for preparation
of primary amine. [2M]
(b)Explain Carbyl amine reaction with equation. (2M]
(c) Arrange the following compounds in the increasing of their basicity.
CH,NH,, CH,NH, NH,
40. (a) Write the products of oxidation of glucose with: (0) Bromine water (i) Nitric acid [2M]
(b) What are fat soluble vitamins? Give an example. [2M]
(c) Name the Nitrogenous base present only in RNA but not in DNA. [1M]
PART -E
(NUMERICAL PROBLEMS)
VIl. Answer any THREE of the following. Each question carries THREE marks: 3 x 3= 9

41. Calculate the osmotic pressure in Pascal's exerted by asolution prepared by dissolving 1.0g
of polymer of molar mass 185,000 g/mol in 450 ml of water at 37°c.

42. The boiling point of Benzene is 353.23K. When 1.80g of non-volatile solute was dissolved
in 90gram of benzene, the boiling point is raised to 354.11K.Calculate the molar mass of

the solute. K, for benzene is 2.53 KKg/ mol

43.
For the standard cell Cu, /Cuo | Agio) /Ag:
=+0.34V EAg*IAg = +0,80V.
(0) ldentify the cathode and the anode as the current is drawn from the cell.
(ii) Write the reaction taking place at the electrodes.
(i) Calculate the standard cell potential.
44. The cell in which of the following reaction occurs: 2Fe (aq) +2/ço) ’2Fea) + ls) has
E,
cell =0.236V at 298K. Calculate the standard Gibbs energy change and the equilibrium
Constant of the cell reaction.

45. The rate constants of a reaction at 500K and 700K are 0.02 s and 0.07s-!
respectively. Calculate the values of E,. Given that (R= 8.314 J. K.mol-)

46. Half life period of a first order reaction is 30 minutes. Calculate the time required to complete
80% of the reaction.

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