HP Board 12th Class Model Question Paper 2025 Chemistry

HPBOSE
MODEL QUESTION
PAPERS

HIMACHAL PRADESH BOARD OF SCHOOL EDUCATION DHARAMSHALA
Model Question Paper- 2024-25

Subject: Chemistry Time 3Hrs
Class XII MM 60

Note:
i. There will be 28 questions in all.
a. Q.N. 1 to 12 are Multiple choice questions and Carry 1 mark each,
b. Q.N. 13 to 19 are Very short answer questions carrying 2 Marks each,
c. Q.N.20 to 24 are short answer questions carrying 3 marks each
d. Q.N. 25 is case study-based question and carries 4 marks
e. Q. 26 to 28 are long answer questions carrying 5 marks each.
ii. All Questions are compulsory however internal choices have been given.

Section A(MCQ)

1. Which of the following factors does not affect the solubility of a solid solute in a liquid solvent?
a) Temperature b) Pressure
c) Nature of the solute and solvent d) Particle size of the solute 1
2. In an electrochemical cell reduction takes place at
a) Cathode b) Anode
c) Salt bridge d) None of these 1
3. With increase in temperature, the conductivity of ____ increases
a) Cu b) Wood
c) Si d) Pt 1
4. The standard electrode potential of a half-cell is measured under standard conditions, which include:
a) 1 M concentration of solutions, 298 K temperature, and 1 atm pressure
b) 0.1 M concentration of solutions, 273 K temperature, and 1 atm pressure
c) 1 M concentration of solutions, 273 K temperature, and 1 atm pressure
d) 0.1 M concentration of solutions, 298 K temperature, and 1 atm pressure 1
5. The most basic among the following is

a) b) CH3NH2

c) CH3CH2NH2 d) 1

6. The number of unpaired electrons in Fe3+ is
a. 3 b. 4
c. 5 d. 6 1
7. In the chlorination of benzene, the role of anhydrous AlCl3 is to:
a) Absorb HCl
b) Act as an oxidizing agent
c) Provide Cl₂
d) Act as a catalyst 1
8. Which of the following is the correct IUPAC name for CH3-CHO?
a) Ethanal b) Methanal
c) Ethanol d) Methanol 1
9. Aldehydes and ketones undergo nucleophilic addition reactions due to the presence of:

a) Electron-rich carbonyl carbon
b) Electron-deficient carbonyl carbon
c) Electron-rich carbonyl oxygen
d) Electron-deficient carbonyl oxygen 1
10. The initial conc. in a first order reaction is 32 mol L-1 and t1/2 is 10 min. the conc. in mol L-1 after half an
hour will be
a. 4 b. 3.2
c. 0.693/32 d. 320 1
11. Assertion (A): Carboxylic acids have higher boiling points than aldehydes and ketones of similar
molecular weight.
Reason (R): Carboxylic acids form strong hydrogen bonds with themselves, leading to the formation of
dimers.
(a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion
(A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true. 1
12. Assertion (A): Phenol is more acidic than ethanol.
Reason (R): The phenoxide ion formed after the loss of a proton from phenol is stabilized by resonance,
whereas the ethoxide ion is not.
(a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of
Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of
Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true. 1

Section B (Very Short Answer Questions)

13. Calculate ECell for given cell if EoCellis 2.7V
Mg| Mg2+(0.001M)|| Cu2+(0.0001M)|Cu 2
14. Derive integrated rate equation for first order reaction. 2
15. What is meant by the chelate effect? Explain with an example. 2
16. Explain why ethers are relatively unreactive compared to alcohols.
Or

Explain a test to distinguish between primary, secondary and tertiary alcohols. 2
17. Aldehydes are more reactive than ketones, why? 2
18. Write a short note on Reimer Tiemann Reaction. 2
19. Explain Secondary Structure of proteins. 2
Section C (Short Answer Questions)

20. a. Give the IUPAC name of K3[Al(C2O4)3].
b. Draw and discuss the structure of [Co(NH3)6]3+ ion, mentioning hybridization and magnetic
character using VBT. 1,2
21. What is fuel cell? Explain the working of H2 – O2 fuel cell. 1,2
OR
a) How much electricity is required to obtain 4g of Calcium by the electrolysis of CaCl2?

b) Give the units of molar conductance. 2,1
22. A first order reaction is 90% complete in 27 minutes, when will the same reaction be 99% complete
under similar conditions? 3
23. a. Phenol is more acidic than ethanol, why?
b. What happens when Propan-2-ol is heated with H2SO4 at 443K? 2,1
24. a. Compare and contrast DNA and RNA in terms of their structure, function, and components.
b Give chemical name of Vitamin D. 2,1
Section D ( Case study Questions)
25. Context:
A researcher is studying the reactivity of different haloalkanes and haloarenes with various reagents. She
compares the reaction of chloromethane (CH₃Cl) and chlorobenzene (C₆H₅Cl) with the following
reagents: aqueous sodium hydroxide (NaOH), aqueous silver nitrate (AgNO₃), and magnesium in dry
ether. She observes distinct differences in reactivity between the haloalkane and haloarene.
Answer following Questions:
a. Write the chemical equation for the reaction of chloromethane with aqueous NaOH and what is the
type of this reaction? 2
b. Explain why chlorobenzene does not undergo a similar reaction with aqueous NaOH as
chloromethane. 2

Section E (Long Answer Type Questions)
26. a. Write a short note on Coupling Reaction.
b. What happens when propanamide is heated with Bromine in alcoholic KOH?
c. How will you convertAniline to Phenol 2,1,2
Or

A compound X with the molecular formula C3H7NO reacts with nitrous acid (HNO2) to form a
compound Y which gives a brisk effervescence with NaHCO3. On heating, X with a dehydrating
agent like P2O5 produces Z with a pleasant odour.
(a) Identify X, Y, and Z.
(b) Write the chemical equations for the reactions involved. 3,2
27. a. A solution is prepared by dissolving 5 grams of sodium chloride (NaCl) in 100 grams of water.
Calculate the molality of the solution. (Molar mass of NaCl = 58.5 g/mol)
b. Give four differences between Ideal and non-ideal solutions 3,2
28. a. Why do transition elements form-coloured compounds?
b. What is Lanthanoid contraction? Give its cause.
c. Why do transition elements show variable oxidation states?
d. What happens when Acidified KMnO4 reacts with FeSO4? 1,2,1,1

ChapterwiseMarksdistributionandBlueprintofXIIChemistryPaper
Session2024-25
Note:
i. There will be 28 questions in all.
a. Q.N. 1 to 12 are Multiple choice questions and Carry 1 mark each,
b. Q.N. 13 to 19 are Very short answer questions carrying 2 Marks each,
c. Q.N.20 to 24 are short answer questions carrying 3 marks each
d. Q.N. 25 is case study-based question and carries 4 marks
e. Q. 26 to 28 are long answer questions carrying 5 marks each.
ii. All Questions are compulsory however internal choices have been given.

S.N. Chapter 1 2 3 4 5 Total
Mark Marks Marks Marks Marks
MCQ
1 Solutions 1 1 6
2 Electrochemistry 3 1 1 8
3 ChemicalKinetics 1 1 1 6
4 Transitionmetals 1 1 6
5 CoordinationCompounds 1 1 5
6 HaloalkanesandHaloarenes 1 - 1 5
7 Alcohols,Phenolsandethers 1 1 1 6
8 Aldehydes,ketonesandcarboxylicacids 3 2 7
9 OrganicCompoundscontaining 1 1 6
Nitrogen
10 Biomolecules 1 1 5
Total Questions 12 7 5 1 3
Total Marks 12 14 15 4 15 60

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