XI Chemistry Model Question Paper 2024-25 PDF

Model Question Paper 2024-25 XI Chemistry Time Allowed 3 Hours MM 60 Note: 1. Thereare28questionsinall. a. Q.N. 1 to 12 are multiple choice questions and Carry 1 mark each, b. Q.N. 13 to 19 are very sh...

Model Question Paper 2024-25 XI Chemistry Time Allowed 3 Hours MM 60 Note: 1. Thereare28questionsinall. a. Q.N. 1 to 12 are multiple choice questions and Carry 1 mark each, b. Q.N. 13 to 19 are very shortanswerquestionscarrying 2 Marks each, c. Q.N.20 to 24 are shortanswerquestionscarrying3 marks each d. Q.N. 25 is case study-based question and carries 4 marks e. Q. 26 to 28 are longanswerquestionscarrying 5 marks each. 2. All Questions are compulsory however internal choices have been given. 3. Students can use log3 = 0.4771 where required. Section A (Multiple Choice Questions) 1. The empirical formula of benzene is a) C6H6 b) CH c) C12H22O11 d) C6H12O6 1 2. The angular momentum of an electron in the nth orbit is given by: a) n×h b) c) d) 1 3. The maximum number of electrons that can be accommodated in a subshell is given by: a) 2l +1 b) 2n2 c) 4l+2 d) 2(2l+1) 1 4. Which of the following molecules has a linear shape? a) H₂O b) NH₃ c) CO₂ d) CH₄ 1 5. The equilibrium constant (K) for the reaction aA+bB⇌cC+dDis given by: [ ] [ ] a) [ ] [ ] [ ] [ ] b. [ ] [ ] [ ] [ ] c. [ ] [ ] [ ] [ ] d. [ ] [ ] 1 6. Which of the following is a redox reaction? a) HCl+NaOH→NaCl+H2O b) CuO+H2→Cu+H2O c) AgNO3+NaCl→AgCl+NaNO3 d) Na2SO4+BaCl2→BaSO4+2NaCl 1 7. The functional group in an alcohol is: a) -CHO b) -COOH c) -OH d) -NH₂ 1 8. The number of sigma and pi bonds in benzene are……...respectively. a) 6,3 b) 6,6 c) 12,3 d) 3,12 1 9. Which of the following is an alkyne? a) Ethylene b) Propane c) Propyne d) Ethane 1 10. Which of the following reactions involves the addition of hydrogen to an unsaturated hydrocarbon? a) Hydration b) Halogenation c) Hydrogenation d) Dehydration 1 Assertion and Reasoning Questions Which of the following is correct for question number 11 and 12? a) Both A and R are true, and R is the correct explanation of A. b) Both A and R are true, but R is not the correct explanation of A. c) A is true, but R is false. d) A is false, but R is true. 11. Structure of Atom:Assertion (A): Electrons in the same subshell have the same energy. Reason (R): Electrons in the same subshell are located in orbitals with the same shape. 1 12. Equilibrium:Assertion (A): At equilibrium, the concentrations of reactants and products remain constant over time. Reason (R): At equilibrium, the forward and reverse reactions stop occurring. 1 Section B (Very Short Answer Questions) 13. Explain the significance of the azimuthal and magnetic quantum numbers. 2 14. Define Ionization enthalpy. Explain the trend of ionization energy across a period and down a group. 2 15. State and explain the first law of thermodynamics. 2 16. Calculate the work done when 2 moles of an ideal gas expand reversibly and isothermally at a temperature of 300 K from an initial volume of 10 L to a final volume of 30 L. Assume the gas behaves ideally. 2 17. Explain Carius method to estimate the percentage of halogen in an organic compound. 2 18. What is isomerism? Write the functional isomers of propanone. 2 19. Alkynes are more acidic than alkanes why? OR Explain the Markovnikov’s rule with an example. 2 Section C (Short Answer Questions) 20. State Pauli exclusion principle and Hund’s rule of maximum multiplicity. 1½ , 1½ Or a) State Heisenberg’s Uncertainty Principle. b) Calculate wave number of radiations having frequency of 4× 10 11 Hz. 1,2  21. a) Define electron gain enthalpy. Explain why electron gain enthalpy of fluorine is less negative than that of chlorine. b) Give the cause of periodicity in periodic properties. 2,1 22. a) Explain Gibbs free energy and its significance in predicting the spontaneity of a reaction. b) What will be the sign of ∆𝑆 for the reaction 2Cl(g) → Cl2(g) ? 2,1 23. a) Balance the following equation in acidic medium. Cr2O72−+C2O42−→Cr3++CO2 b) Calculate Oxidation number of Cr in K2Cr2O7. 2,1 24. a) Write the IUPAC name of CH3-CH=CH-CH2OH. b) Arrange the following in increasing order of acidic strength and give reason for your answer Cl3CCOOH, Cl2CHCOOH and ClCH2COOH 1,2 Section D (Case study Questions) 25. Case Study: The Haber Process The Haber process is used to synthesize ammonia (NH3) from nitrogen (N2) and hydrogen (H2) gases. The balanced chemical equation for the reaction is:N 2(g)+3H2(g)⇌2NH3(g) In an industrial setup, this reaction is conducted at high pressure (around 200 atmospheres) and high temperature (about 450°C) though forward reaction is exothermic in the presence of a catalyst. Questions: a) Explain how increasing the pressure affects the position of equilibrium in the Haber process. b) Predict the effect of increasing the temperature on the equilibrium position of the Haber process. c) Describe the role of the catalyst in the Haber process. d) Write the equilibrium constant expression for the Haber process. 1,1,1,1 Section E (Long Answer Type Questions) 26. a) What is the Volume occupied by 0.5 mole of nitrogen gas at NTP? b) An organic compound contains C = 40% , H = 6.67 % & O = 53.33 % Calculate its empirical formula. c) Define Limiting Reagent. 2,2,1 27. a) BH3 is non polar whereas NH3 has net dipole moment Why? b) Write four differences between sigma(σ) and Pi(π) bond. c) Ice floats over water, why? 2,2,1 28. a) Write a short note on Friedel Craft’ Reaction. b) How will you prepare butane from ethane? c) Complete the reaction. CaC2 + H2O → ----- + ------ 2,2,1 Chapter wise Marks distribution and Blueprint of XI Chemistry Paper Session 2024-25 There will be 28 questions in all. Q.N. 1 to 12 are Multiple choice questions and Carry 1 mark each, Q.N. 13 to 19 Very short answer questions carrying 2 Marks each, Q.N.20 to 24 short answer questions carrying 3 marks each Q.N. 25 is case study-based question and carries 4 marks Q. 26 to 28 Long answer questions carrying 5 marks each. S.N. Chapter 1 2 3 4 5 Total Mark Marks Marks Marks Marks 1 Some Basic Concepts of Chemistry 1 1 6 2 Structure of Atom 3 1 1 8 3 Classification of elements and periodicity in - 1 1 5 properties 4 Chemical bonding and Molecular structure 1 1 6 5 Chemical Thermodynamics 2 1 7 6 Equilibrium 2 - 1 6 7 Redox Reactions 1 - 1 4 8 Organic Chemistry: Some basic principles and 2 2 1 9 Techniques 9 Hydrocarbons 2 1 1 9 Total Questions 12 7 5 1 3 Total Marks 12 14 15 4 15 60