BSc Chemistry SEM III 2017 2018 2018 Chemistry Paper II Question Paper - Mumbai University | munotes

Questions asked in this paper

1. Q2 Answers to the same question must be written together
2. Q3 Figures to the right indicate full marks
3. Q4 Use of non-programmable calculator logarithm table is permitted
4. Q1 (A) Select the correct option and complete the following sentences :—
   • (i) Nitration of phenol is an example of reaction
   • (a) consecutive (b) (c) opposing
   • (ii) The correct form of Arrhenius equation is
   • (iii) Ideal solution is formed when its components
   • (a) have zero heat of mixing only
   • (b) have zero heat of mixing and zero volume change
   • (c) can be converted into gases
   • (iv) For the study of distribution law the two solvents should
   • (a) immiscible miscible
   • (v) Tincal and Suhagain are the naturally occuring ores of
   • (vi) among the following elements has remarkably low melting point and expands when it forms.a solid (vil) All elements in group-14 show covalency greater
   • (viii) is extracted from ore
   • (ix) The aldehyde used in the Knoevengal reaction is having
   • (c) —H atom
   • (x). 2 - chloropentanal is
   • (xi) The active methylene group will have groups attached to it
   • (a) —CN and NO,
   • (c) —NHCOR and COR (xil) The general structure of enamine is
   • (B) State whether the following statements are true or false : — 3
   • (i) The rate of most of the reactions increase considerably with increase in
   • (iii) Aldehydes are usually more reactive towards nucleophilic reagents than
   • (C) Match the columns :— 5
   • (i) Units of Energy of activation (a) Partially miscible with upper and
   • (iii) +3 oxidation state (c) Carbon
   • (f) Aluminium
   • (h) — Thallium
5. Q2 (A) Explain the application of Collision Theory to Bimolecular reactions. 5 marks
   • (ii) Give any three merits of Collision Theory. 3
   • (A) What are Chain carriers ? Explain the important steps in a chain reaction. 5 Explain reversible reactions giving a suitable example. 3
   • (B) (i) With the help of vapour pressure-composition diagram explain positive 5 deviations from Raoult's law
   • (ii) Give three applications of distribution law. 3
   • (B) Discuss the variation of mutual solubility with temperature for the ‘Phenol- 5
   • (ii) Give the techniques used to separate the components of an azeotropic mixture. 3
   • (C) For a first order reaction : 2N,O, NO, Ox.) ; the frequency factor ‘A’is 4 4-3 x and is 103-35 What is the rate constant ?
   • (C) A mixture of water and aniline boils at a temperature of at pressure of 4 1-013 x The vapour pressure of water at this temperature is 9-558 x Find the composition of the distillate [Given : Molecular weight of water = 18, molecular weight of aniline = 93]
6. Q3 (A) (i) Discuss the gradation in properties of group 13 elements with respect radii and Ionisation energy values 5 marks
   • (ii) Give a brief account of structure of Diborane. 3
   • (A) G) Explain the purification of by zone refining technique. 5
   • (ii) ‘Zone refining technique is not effective for the purification of silicon’.Give 3
   • (B) Write notes on ‘Oxidation states’ exhibited by the elements of group 15. 5
   • (ii) Name the hydrides of group 15 elements. Give an account of the physical 3 state and solubility of these hydrides
   • (B) (i) Discuss the preparation of borax from ‘boric acid’. Mention any 5 properties and any two uses of borax Give an account of one method of preparation, and the physical properties of 3
   • (C) Discuss the structure of 4
   • (C) Explain why boron trihalides can act as Lewis acids. 4
7. Q4 (A) Explain the mechanism of Benzoin Condensation. 5 marks
   • (ii) Give preparation of succinic acid from ethyl aceto acetate. 3
   • (A) (i) (a) Give preparation of benzaldehyde and acetophenone by oxidation of 3
   • (b) What are stabilised enols ? 2
   • (ii) How will you obtain isobutyric acid from ethyl acetoacetate ? 3
   • (B) G) (a) Complete the following reactions and explain the role of BaSO, in
   • (b) Discuss the reduction of propanal by using LiAIH,. 2
   • (ii) Give the mechanism of acid catalysed 3
   • (i) (a) Write a note on Gattermann - Koch formylation. 3
   • (b) Discuss the reduction of 2-butenal by using 2
   • (ii) Explain the general mechanism of nuclephilic addition to carbonyl compound. 3
   • (C) Discuss the synthesis of primary, secondary and tertiary alcohols from Grignard 4
   • (C) Explain the preparation of acetal and cyclic acetal from ethanal. 4
8. Q5 Attempt any four :—
   • (A) State and explain any five conditions for the validity of Nernst Distribution Law. 5
   • (B) Compare the Collision Theory with the Activated Complex theory of reaction rates. 5
   • (C) How is silicon purified by Czochralski pulling technique ? 5
   • (D) Give an account of the synthesis of NH, by Haber's process. 5
   • (E) Explain the mechanism of Claisen - Schmidt reaction. 5
   • (F) Give the IUPAC name of CH,CHO, give its preparation using grignard reagent. 5 What is the action of HCN on CH,CHO ?

Read from the scan above, so a character or two may differ. The scan is the original.