BSc Chemistry SEM III ATKT CHEMISTRY PAPER II Question Paper - Mumbai University | munotes

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• 2. Figures to the right indicate full marks

1. Q3 Use of log-table nonprogrammable calculator is allowed
2. Q4 Answers for the same question as far as possible should be written together
3. Q1 Select the correct option and complete the following sentences. (any twelve) 12 marks
   • (i) Solution is a mixture of two or more non-reacting substances
   • (ii) By fractional distillation constituents of can be separated
   • (a) non ideal solution (b) ideal solution (c) any mixture The plot of log k versus is linear with a slope
   • (iv) In a chain reaction, the reactive intermediates like atoms or free radicals are produced in chain step
   • (v) Chlorination of toluene isan example of
   • (vi) The temperature at which two conjugate solutions merge into one another to form a single layer is called
   • (c) evaporation temperature
   • (vii) In diborane molecule, number of terminal B-H bonds are (Vili) Molecular formula of borax is
   • (a) Na2B407.10H20 (b) (c)
   • (ix) Silicon tetrachloride has structure
   • (x) the incorrect statement
   • (a) Silicon is extensively used as a semiconductor
   • (b) Silicon occurs in free state in nature
   • (c) is inert
   • (xi) Thermal stability of hydrides gradually from to In nitrous oxide, oxidation state of nitrogen is The aldehyde used in the Knoevenagal reaction has
   • (a) a-H atom (b) a- and B-H atom (c) no a-H atom
   • (xiv) The hybridisation of ‘C’ and ‘O’ in the >C = O group is
   • (xv) Friedel Craft acylation of benzene can be carried out by using
   • (xvi) The general structure of enamine is
   • (xvii) The aldehyde used in the Cannizzaro reaction has
   • (a) a-H atom (b) a- and B-H atom (c) no a-H atom (xviii) may be prepared by the action of one mole of CH3MgI on ethyl formate followed by hydrolysis of addition product
   • (B) State whether the following statements are true or false. (any three) 3
   • (i) For the study of distribution ratio, the two solvents must be miscible with
   • (iii) does not exist in free form
   • (iv) In silicon dioxide each silicon atom is bonded to four oxygen atoms and each oxygen atom is bonded to two silicon atoms
   • (v) | Ifacompound contains both aldehyde and ketonic group, then the aldehyde is considered as the parent compound
   • (vi) Ketones are usually more reactive towards nucleophilic reagent than
   • (C) Match the column. (any five) 5
   • (iii) NH3 (c)
   • (h) Square planar
4. Q2 Attempt any four of the following. 20 marks
   • (A) State and explain Nernst’s distribution law. What are its important applications?
   • (B) State Raoult’s law. With the help of suitable diagrams explain positive and negative deviations from Raoult’s law
   • (C) The vapour pressures of pure benzene and toluene at are and Nm” respectively. Mole fraction of benzene in the solution is 0.40 Assume that the solution is an ideal one. Calculate
   • (i) the partial pressure of benzene and toluene
   • (ii) total vapour pressure of the solution and
   • (iii) the mole fraction of benzene in the vapour above the solution
   • (D) State the important assumptions of the collision theory of reaction rates. What are the drawbacks of this theory?
   • (E) What is meant by ‘energy of activation’ in kinetic studies? How it is determined
   • (F) For the reaction, CoHsI+ OH — + the rate constants were found to be at 289 K and 6.71 at 333K.Calculate the energy of activation for the
5. Q3 Attempt any four of the following. 20 marks
   • (A) Among BF3 and BCls, who is strong Lewis acid ? Explain
   • (B) Draw of tetraborane. How many terminal and bridge bonds are in its structure ? Calculate total number of electrons involved in it
   • (C) What is silica ? Why is it inert ?
   • (D) Explain zone refining technique for the purification of germanium
   • (E) Find oxidation state of nitrogen in N2Os and explain their structures
   • (F) Explain synthesis of ammonia by Bosh - Haber process
6. Q4 Attempt any four of the following
   • (A) 1) Give preparation of benzaldehyde and acetophenone by oxidation of alcohol 3 1i) Discuss the reduction of 3-phenyl-2-propenal by using 2
   • (B) i) Explain general mechanism of acid catalyzed nucleophilic addition to 3 How is primary alcohol obtained from Grignard reagent? 2 Give preparation of: 5
7. Q1 2-butanone from acetyl acetone 1i) succinic acid from acetoacetate
   • i) Write a note on Rosenmund reduction. 3 How benzaldehyde cynohydrin and benzaldehyde phenyl hydrazone are 2 obtained from benzaldehyde?
   • (E) Give the mechanism of base catalyzed enolisation. 3
   • ii) Discuss the reduction of 2-butenal by using 2
   • (F). Explain the mechanism of Claisen-Schmidt reaction. 5
8. Q5 Attempt any four of the following
   • (A) What are the important steps involved in a chain reaction? Explain the steps 5 involved in the reaction between hydrogen and bromine
   • (B) At560 K, at of 1 mol the number of XY molecules colliding per cm? per second is If the activation energy of the reaction, 2XY X2+ Y2 is calculate the number of XY molecules reacting
   • (C) Write a note on formation of trihalides and pentahalides of the elements of nitrogen 5
   • (D) With suitable diagram, explain Czochralski pulling technique for purification of 5
   • (E) i) Write a note on Gattermann — Koch formylation. 3 What are active methylene compounds? Why are they considered as carbon 2
   • (F) Explain the mechanism of benzoin condensation. 5

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