Microsoft word - chemistry q p 2010

MODEL EXAMINATION Part III Time : 2 Hours HSE (II) Cool of Time : 15 Min Total Score : 60 Feb 2010 General Instructions to Candidates: * There is ‘Cool of time’ of 15 minutes in addition to the writing time of 2hrs. * You are not allowed to write your answers nor to discuss anything with others during the ‘Cool of time’ * Use the ‘Cool of time’ to get familiar with questions and to plan your answers. * Read questions carefully before answering. * All questions are compulsory and only internal choice is allowed. * When you select a question, all the sub questions must be answered from the same question itself. * Calculations, figures and graphs should be shown in the answer sheet itself. * Malayalam version of the questions is also provided. * Give equations where necessary 1 (a) Calculate the number of atoms present per unit cell of Ag which crystallises in f.c.c lattice? (2) (b) Explain how Schottky and Frenkel defects are developed in ionic crystals? (2) 2 (a) Describe the solutions with positive and negative deviations graphically (2) (b) 200cm3 of an aqueous solution of a protein contains 1.26g of a protein. The osmotic pressure of such a solution at 300K is found to be 2.57x10-3 bar. Calculate the molecular mass of protein (a) Scientists suggest the use of fuel cell as an alternative to conventional fossil fuels. Explain the working of such a fuel cell with diagram (1.5) (b) Calculate the molar conductance at infinite dilution of NH4OH given that Λ∞m for NaCl, NaOH, NH4Cl are 126.4, 248.1 and 129.8 ohm-1cm2mol-1 (1.5) OR You are given the following standard electrode potential values Eo 3+ Draw a neat diagram of the Daniel cell using the above electrodes.Write the electrode reactions (2) Calculate the e.m.f of the above cell (1) 4 (a) Differentiate between order and molecularity of a reaction (2) (b) The rate of a reaction doubles when temperature is increased from 300K to 310K.Calculate 5 (a) Which of the following electrolyte is most effective for the coagulation of As2S3 sol K2SO4, BaSO4, Al2(SO4)3 (1) (b) State the rule which governs your choice (2) 6 (a) Suggest a method for obtaining extrapure Ge and Si (1) (b) Briefly explain Mond process for refining Nickel (2) 7 (a) Give a method for preparation of PH3 (1) (b) Name two allotropes of phosphorus (1) (c) Sketch the structure of XeF4 (1) (d) In contact process, what happens when SO3 is absorbed in Conc. H2SO4 (2) 8 (a) Among the divalent cations of first transition series ,Mn2+ shows maximum paramagnetic moment.Explain (2) (b) Give two examples for the oxidising property of KMnO4 in acidic medium (2) 9 (a) Give the IUPAC names of (i) [Co(H2O)6]Cl2 (ii) K4[Fe(CN)6] (iii) [Ni(en)3]Cl3 (3) (b) Briefly explain linkage isomerism in co-ordination compounds (1) 10. (a) Which compound in the following pairs will react in SN2 reaction with OH- ion ( i ) CH3Br or CH3I ( ii ) (CH3)3CCl or CH3Cl (2) (b) The treatment of alkyl chloride with aq. KOH leads to the formation of alcohols but in the Presence of alc.KOH, alkenes are the major products. Explain (2) 11. Give reasons for the following facts. (a) Phenols are million times more acidic than alcohols (2) (b) How will you distinguish between primary,secondary,and tertiary alcohols using Lucas reagent (2) 12. You are provided with the following reactants and reagents Reactant Reagent CH3COCH3 Zn- amalgum/conc.HCl (a) Name the reaction and predict the product in each case (3) (b) Write the chemical equations involved in atleast two cases (2) 13. (a) Arrange the following amines in the increasing order of basicity CH3NH2, (CH3)2NH , (CH3)3N , NH3 , C6H5NH2 (1) (b) Give reasons for your choice (2) OR (a) How will you convert aniline in to phenol (2) (b) CH3NH2 + CH3Cl3 + 3KOH 14. Define the following as related to proteins (i) Peptide linkage (ii) Zwitter ion (iii) Denaturation (3) 15. (a) Name and give the structure of monomer units of natural rubber (1) (b) Name the two commercially important synthetic polymers. Name their monomer units (2) 16. Both antiseptics and disinfectants are used to kill microorganism (a) In what respect they differ from each other? (2) (b) Name a substance which can be used as antiseptic and disinfectant (1) OR Match the following

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