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Class: Preliminary Examination -2018 You will not be allowed to write during the first 15 minutes This time is to be spent in reading the question paper. Answer all questions are compulsory Question 1 is of 20 marks having four sub parts all of which are compulsory. Question numbers 2 to 8 carry 2 marks with two questions having internal choice. Question numbers 9 to 15 carry 3 marks with two questions having internal choice. Question numbers 16 to 18 carry5 marks each. Each question has an internal choice. Some useful constants - R=0.0821 latmK-1mol-1, 8.314 JK-1mol-1 h=6.626 x 10 -34Js Me =9.1 X 10 -31 Kg, C= 3 x 108 m/s. Atomic weight: H=1, C=12, N=14, O=16, Na=23, Mg=24, Al=27, K=39, Cr=52 P=31, S=32, Cl=35.5, Ca=40, Fe=56, Cu=64, He=4, Li=7Mn=55 Atomic number:Cr=24,Cu=29, H=1, N=7, Na=11,Al=13, He=2,Li=3 Question 1 a) Fill in the blanks by choosing the words from those given in the brackets: [4] [+ 3 ,lower,atoms, acidic, positive,reduction, +4, hydrogen , basic, 8, negative, no gas, molecules ,+6, heat, sp3, carbon dioxide, ions, oxidation, - 3] i) ii) iii) iv) The crystal of graphite is made up of _______ while that of sodium chloride is made up of _______. Lithium has the highest standard ________ potential value and fluorine has highest standard _______ potential value. Oxidation state of Phosphorous in phosphine is _______ and sulphur in pyrosulphuric acid is _____ Phenol reacts with sodium metal and liberates ______ gas and on treatment with sodium bicarbonate releases ________ . b) Select the correct alternatives from the choices given : [4] i) A solution of 0.450 g of urea (mol.wt. 60) in 22.5 g of water showed 0.1700C of elevation in boiling point. The molal elevation constant of water is a) 0.510C. b) 0.950C c) 0.250C d) 2.250C ii) Which isomer of C4H9Br will produce 2-methylpropan-2-ol by treatment with aqueous KOH? a) n-butyl bromide b) Isobutyl bromide c) Tertiary-butyl bromide d) Sec-butyl bromide iii) Which among the following gives aldol condensation reaction? a) phenol b) benzophenone 1
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