Class XI CBSE Chemistry Model Paper

Chemistry

Class – XI

Time – 3 Hrs. Marks – 70

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General Instructions :

i) All questions are compulsory.

ii) Q. s 1 to 8 carry 1 makes each. Answer them in one word or in about on sentence.

iii) Q. s 9 to 18 carry 2 marks each. Answer these in about 30 words each.

iv) Q. s 19 to 27 carry 3 marks each. Answer these in about 40 words each.

v) Q. s 28 to 30 are long answer questions carrying 5 marks each.

vi) Use long table if necessary, use of calculator is not permitted.

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1. Write IUPAC name of the following compound : 1

 
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2. Write down the formula of the monomer of silicone. 1

3. What would be the effect of increasing pressure on the equilibrium. 1

PCl5 (g) = Pcl3 (g) + Cl2 (g) ?

4. What is the oxidation number of oxygen in Na2O2 ? 1

5. What would be the sign of S for the process 2H (g) à H2 (g) ? 1

6. What is compressibility factor of a gas ? 1

7. Configuration of ion M+2 is Is2 2s2 2p5 what is configuration of atom M? 1

8. How many oxygen atoms would be there in 1 mole of H2SO4 ?

9. clip_image004 a) What is the hybridization of each carbon in CH3 – CH2 ? 1

b) What is the function of AlCl3 (anhyd) in Friedel Crafts reaction ? 1

10. How N and S are detected when present in an organic compound together ? (Reaction only) 2

OR

Which is the electrophillic centre in CH3Br and why ?

11. Why lithium does not form a superoxide but potassium does ? 2

OR

Why BeSO4 is water soluble but BaSO4 is not ?

12. Balance the following redox feaction by ion 2

Electron method :

Cr2 O7-2 + Fe+2 à Fe+3 + Cr+3 in acidic medium.

13. a) What is the change in internal energy in a process in which 700J of heat is absorbed and 450J of work is done by the system ?

b) Define a spontaneous process in terms of Gibbs energy. 1

14. Show by MO concept which one out of O2 and O2+ would be more stable. 2

OR

Explain all the orbital overlaps in a molecule of ethene (C2H4) by drawing a sutitable diagram.

15. Calculate the mass of (NH4)2 S required to prepare 200 ml of O.1 molar aqueous solution.

(N = 14, H = 1, S = 32)

16. a) Write down the IUPAC name and symbol of the element with at no 119. 1

b) Why Cl has more negative electron gain enthalpy then F in group 17 ? 1

17. Arrange the species : F, O-2, N-3, Mg + 2, Al + 3 and Na+ in the increasing order of ionic radii and give reason. 2