Q21) Give an example of each with necessary reaction conditions :
(i) Sandmeyer's reaction
(ii) Kharasch Effect (Marks 2)

Q22) What is 'inert pair effect'? Discuss the oxidation states of Group 13 elements in relation to this effect. (Marks 2)

Q23) A co-ordination compound has the formula CoCl₃.4NH₃. It does not liberate ammonia but precipitates chloride ions as silver chloride. Give the IUPAC name of the complex and write its structure formula. (Marks 2)

Q24) Write the information asked for in the following polymers :
(i) Bakelite : material used for preparation
(ii) Synthetic rubber : monomer unit
(iii) PVC : monomer unit
(iv) Nylon-66 : materials required for preparation.  Marks 1)

Q25) "The two strands of DNA are not identical but are complementary." Explain this statement. (Marks 2)

Q26) Write the structure of adenosine triphosphate indicating clearly the energy rich bonds. How does this molecule form the source of energy?  (Marks 2)

Q27) Explain how an electron can be considered to have a particle as well as nature. A moving electron has 4.9 x 10^-25 joules of kinetic energy. Find out its De Broglie wavelength.
(Given h = 6.6x10^-34 Js; m = 9.1x10^-31 kg) (Marks 3)

Q28) An aqueous solution freezes at 272.4 k, while pure water freezes at 273.0 K. Determine :
(i) the molality of the solution,
(ii) boiling point of the solution,
(iii) lowering of vapour pressure of water at 298K.
[ Given K_f = 1.86 K kg mol^-, K_b = 0.512 K kg mol^-1 and vapour pressure of water at 298 K = 23.756 mm Hg ] (Marks 3)

Q29) (a) When NH₄NO₂ (s) decomposes at 373 K, it forms N₂(g) and H₂O(g). The H for the reaction at one atmosphere pressure and 373k is -223.6 kJ mol^-1 of NH₄NO₄(s) decomposed. What is the value of E for the reaction under the same conditions?
[ Given R = 8.31 JK^- mol^-1 ]
(b) Account for the fact that E is numerically bigger H in the above case.  (Marks 3)

Q30) What is meant by the colloidal state of matter? Explain the following terms :
(i) Multi-molecular colloids
(ii) Elector-dialysis (Marks 3)

Q31) An organic compound A having molecular formula, C₆H₆O give a characteristic colour with aqueous FeCl₃ solution. A on treatment with CO₂ and NaOH at 400 K under pressure gives B which on acidification gives a compund C. C reacts with acetyl chloride to give D which is a popular pain-killer. Deduce the structures of A, B, C and D (Marks 3)

Q32) (a) Write the balanced equations for the following reactions :
                   450 K
(i) BF3 + LiH
(ii) NH3 + NaOCl
(iii) SiCl4 + H2O
(iv) XeF6 + KF
(b) State the reason for the occurrence of "diagonal relationship" in the periodic table. (Marks 3)

Q33) (a) Write the general formula for nitroalkanes and for alkyl nitrites.
(b) How are nitroalkanes prepared alkanes?
(c) What happens when :
(i) nitroethane is treated with lithium aluminium hydride,
(ii) nitrobenzene is reduced with hydrogen using copper oxide as catalyst.
(d) Write two use of nitroalkanes, one each in the laboratory and in the industry. (Marks 5)

Q34) (a) (i) What are inner transition elements? Write their general electronic configuration.
(ii) In what way are the observed oxidation states of the lanthanide's related to their electronic configuration?
(b) Describe the general characteristics of the transition elements with special reference to their tendency to :
(i) exhibit paramagnetism,
(ii) form complex compounds,
(iii) their catalytic behaviour.  (Marks 5)

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