#### Full Portion Two Marks Question Paper

12th Standard EM

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Chemistry

Time : 01:00:00 Hrs
Total Marks : 50
25 x 2 = 50
1. What is the role of Limestone in the extraction of Iron from its oxide Fe2O3?

2. Write a note on Fisher tropsch synthesis

3. What is inert pair effect?

4. Chalcogens belongs to p-block. Give reason.

5. Explain the oxidation states of 3d series elements.

6. Describe the preparation of potassium dichromate.

7. Why Zn2+ salts are white while Ni2+ salts are coloured?

8. Ni2+ is identified using alcoholic solution of dimethyl glyoxime. Write the structural formula for the rosy red precipitate of a complex formed in the reaction.

9. Draw all possible geometrical isomers of the complex [Co(en)2]+ and identify the optically active isomer.

10. Calculate the magnetic moment of [Fe(H2O)6]2+, if atomic number of Fe is 26.

11. What are structural isomers?

12. Explain the rate determining step with an example.

13. The decomposition reaction of ammonia gas on platinum surface has a rate constant R = 2.5 X 10-4mol L-1. What is the order of the reaction.

14. Discuss the Lowery – Bronsted concept of acids and bases.

15. What are the two types of buffer? Give an example for each.

16. Calculate the molar conductance of 0.025M aqueous solution of calcium chloride at
25°C. The specific conductance of calcium chloride is 12.04 × 10-2 Sm-1.

17. What causes Brownian movement in a colloid?

18. Write short notes on bromination of anisole.

19. What is vinegar?

20. Identify compounds A,B and C in the following sequence of reactions.
i) ${ C }_{ 6 }{ H }_{ 5 }NO_{ 2 }\overset { Fe/HCL }{ \longrightarrow } A\overset { HN{ O }_{ 2 } }{ \underset { 273K }{ \longrightarrow } } B\overset { { C }_{ 6 }{ H }_{ 5 }OH }{ \longrightarrow } C$
ii) ${ C }_{ 6 }{ H }_{ 5 }N_{ 2 }cl\overset { CuCN }{ \longrightarrow } A\overset { H_{ 2 }O/H^{ + } }{ \longrightarrow } B\overset { NH_3 }{ \longrightarrow } C$

iii) ${ C }{ H }_{ 3 }{ C }{ H }_{ 2 }I\overset { NaCN}{ \longrightarrow } A\overset {OH^-}{ \underset {Partial hydrolysis}{ \longrightarrow } } B\overset {NaOH+Br_2 }{ \longrightarrow } C$
iv) ${ C }{ H }_{ 3 }NH_{ 2 }\overset { CH_3 Br }{ \longrightarrow } A\overset { CH_{ 3 }COCl}{ \longrightarrow } B\overset { B_2H_6 }{ \longrightarrow } C$
v) ${ C }_{ 6 }{ H }_{ 5 }NH_{ 2 }\overset { (CH_{ 3 }CO)_{ 2 }O }{ \underset { Pyridine }{ \longrightarrow } } A\overset { HNO_{ 3 } }{ \underset { H_{ 2 }SO_{ 4 },288K }{ \longrightarrow } } B\overset { { H }_{ 2 }O/{ H }^{ + } }{ \longrightarrow C }$
vi)

vii) ${ C }{ H }_{ 3 }CN_{ 2 }NC\overset { HgO }{ \longrightarrow } A\overset { H_{ 2 }O }{ \longrightarrow } B\overset { i)\quad NaN{ O }_{ 2 }/HCL }{ \underset { ii){ \quad H }_{ 2 }O }{ \longrightarrow } }$

21. ${ C }_{ 2 }{ H }_{ 3 }N\xrightarrow [ Ether ]{ LiAl/{ H }_{ 4 } } B\underrightarrow { HN{ O }_{ 2 } }$ Identify A, Band C

22. Convertmethylisocyanide ⟶ dimethylamine

23. The two strands in DNA are not identical but are complementary explain.

24. Give the classification of polymers on the basis of their source.

25. Explain why chloroform is not used as an anaesthetic.