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GOLDCREST HIGH-LATUR ON THE WINGS OF EXCELLENCE PRELIM-01 SUBJECT:-CHEMISTRY (PAPER-01) TIME:3 HOURS DATE:-04/01/2017 GRADE: XII MARKS:70 General Instructions (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time) --------------------------------------------------------------------------------------------------------------------Answer all questions in Part I and six questions from Part II, choosing two questions from Section A, two from Section B and two from Section C. All working, including rough work, should be done on the same sheet as, and adjacent to the rest of the answer. The intended marks for questions or parts of questions are given in [ ] Balanced equations must be given wherever possible and diagrams where they are helpful. When solving numerical problems, all essential working must be shown. In working out the problems, use the following Gas constant R = 1.987 cal deg mol- = 8.314 J K- mol= 0.0821 L atm K- mol- 1 L atm = 1dm atm = 101.3J Avogadro s number = 6.023 x 10 -1 1 1 3 1 1 1 23 PART- I (20Marks) (Answer all questions) Question-01 (a)Fill in the blanks by choosing the appropriate word/words from those given in the brackets: [5] (increases, formic acid, decreases, less, zero, small, paired, atoms, unpaired, ions,pentagonal bipyramidal, electrical, more, ethylamine, molecules, propanoic acid,methylamine, chemical) (i) An electrochemical cell converts ________ energy to _________ energy. (ii) The crystal of graphite is made up of ______________ while that of sodium chloride is made up of ---------------- . (iii) Ethyl isocyanide, on hydrolysis with dilute sulphuric acid, gives ______________ and _________________ . (iv) The molar conductance of a solution _______________ with dilution, while its specific conductance _______________ with dilution. (v) The Van t Hoff factor of acetic acid solution is ____________than one and the value of normal colligative property is ____________ than the observed colligative property of this solution. (b)Complete the following statements by selecting the correct alternative from the choices given: [5] (i) The molal freezing point constant of water is 1.86 K Kg mol -1.Therefore, the freezing point of 0.1M NaCl solution in water is expected to be : (1)-1.86 oC (2) -0.372 oC (3) -0.186 oC (4) +0.372 oC -4 -1 (ii) For the first order reaction the rate constant for decomposition of N 2O5 is 6 x 10 Sec .The half life period for the decomposition in seconds is: (1)11.55 (2)115.5 (3)1155 (4) 1.155 (iii)When acetaldehyde is treated with Grignard reagent, followed by hydrolysis the product formed is : (1)Primary alcohol (2) Secondary alcohol (3) Carboxylic acid (4) Tertiary alcohol (iv) The geometry of XeF6 molecule and the hybridization of Xe in the molecule is : (1)Distorted octahedral and sp3 d3 (2) Square planar and sp3d2 (3)Pyramidal and sp3 (4) Octahedral and sp3d3 (v) In the complexs [Fe (CN)6]3- and [Pt(en)(H2O)2(NO2)(Cl)]2+ the respective oxidation numbers of central metal atoms are : (1) +3 and +4 (2) +6 and +4 (3)+6 and +3 (4) +3 and +3
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