BSc Chemistry SEM II 2018 19 May 2018-19 CHEMISTRY PAPER I Question Paper - Mumbai University | munotes

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1. Q2 Answers to the same questions must be written together
2. Q3 Figures to the right indicate full marks
3. Q4 The use of log table/non-programmable calculators is allowed
4. Q1 <A. Select the correct option and complete the following sentences 12 marks
   • i) The van-der Waal’s constant ‘a’ is expressed in the unit
   • ii) velocity for which the fraction of molecule is maximum is
   • c) minimum velocity
   • iii) | Entropy of the medium -------- when salt is dissolved in water
   • iv) the pressure and absolute temperature of the 3 litre of a gas are doubled its volume will be
   • v) The value of equilibrium constant depends on
   • a) temperature b) c) concentration of which follows all assumptions of kinetic theory of gases is called ----- gas vil) Cations have charges
   • ix) The evolution of CO, can be detected by
   • x) is an example of x1) and basic character in non aqueous solvent is not
   • c) Lewis concept Xli) | Cu+ is toxic when present in the body at concentration of mg/kg of body weight
   • xiii) Bromination of propane gives
   • a) 1-bromopropane as major product
   • b) 2-bromopropane as major product
   • c) equal quantities of 1-bromopropane and 2 bromopropane as product
   • xiv) The product of Wurtz reaction is —
   • xv) The products of ozonolysis of 2-butene are
   • a) 2 molecules of CH3CHO
   • c) Imolecule of and 1 molecule of Xvi) is a method for of an alkene Xvil) The ease of dehydration of alcohols is Hydroxylation of alkenes using OsO, is a
   • B. ~ State whether the following statements are true or false 3
5. Q1 At equilibrium free energy does not changes — The free path is the distance travelled by the molecule before
   • iii) According to Pearson, Class ‘a’ metal ions are hard acids
   • iv) dioxide is basic in nature
   • v) of HBr to propene in absence of peroxides follows
   • vi) Relative reactivities of halogens is
   • C. Match the following columns (any five): 5
   • iii) c) carbanion
   • d) Van
   • vi) E;cB mechanism f) state function
   • h) soft base
6. Q2 Answer any four of the following:
   • A. Define Joule-Thompson effect. Show that Joule Thompson 5 effect is isoenthalpic
   • B. Explain the deviation of gases from ideal behaviour using 5
   • C. The free energy change for a reaction at 300 K is -67KJ, the 5 enthalpy change is -42KJ. Calculate the entropy change of the reaction. What will be AG of the reaction at 350K?
   • D. What is meant by equilibrium constant? Derive the relation 5 between K, and Kg
   • F. For a reaction calculate 5 the value of and K, at 327 The equilibrium concentration of are 0.02 and 0.02 respectively
7. Q3 Answer any four of the following:
   • A. How will you detect the presence of ions in the 5 using reagent paper sulphites, sulphides and
   • B. Explain the term precipitation equilibria in qualitative 5
   • C. What is ionic strength? Discuss it’s relation with activity of 5
   • D. Explain classification of substances of acids and bases of 5
   • E. What are the different types of Lewis acids and bases? Give 5 F, What are the limitations of Bronsted-Lowry concept? 5
8. Q4 Answer any four of the following:
   • A. What is a Explain E, mechanism with a 5
   • B. 1) How would you prepare iodide from methane? Why 3 is the yield of the reaction low and how can it be increased? 1i) Explain the reactivity-selectivity principle as applied to 2 halogenation of alkanes
   • C. Write a reaction to show the action of 20% on 2- 5 methyl-2-butanol. Predict the major and minor products. Give reasons for your answer
   • D. Give stepwise reactions for the hydroboration-oxidation of 5 ethane. Name the rule according to which addition takes
   • E. Explain why 5
   • i. Terminal alkynes are weakly acidic in nature
   • ii. Tertiary alkyl halides prefer to undergo E; mechanism as compared to primary alkyl halides
   • F. Write short notes on the following: 5
9. Q5 Answer any four of the following:
   • A. State Le-Chatelier principle. How does it explain the effect of 5 change of variables on the equilibrium?
   • B. 11.0 g of CO; occupied at 298K. Calculate the 5 pressure exerted by the gas using ideal gas equation and Van 4.267 mass of 44
   • C. What are dry and wet test? Explain. 5
   • D. Calculate the pH of solution when 10 cm’ of 0.1M NaOH 5 added to 0.1M HCI, using following stages of titration
   • a) of NaOH added 9.9 of NaOH added
   • E. What is a conjugated diene? Explain 1,2- and 1 4- addition 5 reactions to conjugated dienes with a suitable example
   • F. Explain the mechanism of oxymercuration-demercuration 5

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