BSc Biochemistry Sem III ATKT BIO CHEM CHEMISTRY PAPER I Question Paper - Mumbai University | munotes

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1. Q3 The use of log-table/nonprogrammable calculator is allowed
2. Q4 Answers for the same question as far as possible should be written together A Select the correct option and complete the following sentences: 12
   • (i) The rate of change of free energy with temperature at constant pressure is
   • (ii) Decrease in Gibbs free energy is done
   • (iii) Van’t Hoff reaction isotherm is given as
   • (iv) Specific conductance of a solution is the conductance offered by volume of solution
   • a) 0.1 dm? b) lem?
   • (v) As the temperature increases, resistance of an electrolytic conductor
   • a) increases b) decreases c) does not get affected
   • (vi) At the same temperature, the transport number of an ion will be in solutions of different salts of the ion Vil) Among the following compounds, is expected to be more During the formation of a chemical bond, energy of the system
   • a) decreases b) increases c) does not change 1x) The H—P-—H bond angle in PHs3 is
3. Q10 The number of lone pairs of electrons in NH3
   • xi) The formal charge on H atom in ion is Xil) The contributing structures of a molecule exhibiting resonance should have number of unpaired electrons bromo toluene on treatment with sodamide in presence of liq. ammonia
   • c) mixture of o-amino toluene & m-amino toluene
   • xiv) Chiral alcohol reacts with thionyl chloride to form alkyl chloride XV) Phenols are
   • a) weakly acidic b) strongly acidic c) none of them Xvi) Reaction of epoxide with HCN leads to formation of
   • xvii) Nitration of phenol with gives Xviii) Reaction of ethylene oxide with Grignard reagent followed by acid B State whether the following sentences are True or False 03
   • (i) In electrolytic conductors, transfer of matter does not take place
   • (ii) Chemical potential is the Gibbs free energy of 1 mole component present (ili) d orbitals are un-gerade in nature
   • iv) BF3 molecule has two lone pairs of electrons
   • (v) Ethyl alcohol has lower boiling point than Dimethy] ether
   • vi) p-nitrophenol is more acidic than phenol C Match the following — (any five) 05 Attempt any four from the following— B Explain the variation of chemical potential with pressure and temperature. 05 C Explain - whether the following process- 05 iS spontaneous or non-spontaneous at 298 K under standard state of conditions. (Given - At 298K, = -91 kJ and = 41.5 JK"! for this D i) State Kolhrausch’s law of independent migration of ion. 05
   • ii) The values of molar conductance at infinite dilution for sodium acetate, hydrochloric acid and sodium chloride are 0.00910, 0.04261 and respectively. Calculate the molar conductance of acetic acid at E Define the terms — 1) conductance, ii) specific conductance, i1i) cell constant, 05
   • iv) molar conductance and v) transport number F Describe the factors affecting the transport number. 05 Attempt any four from the following— A Define following terms: a) heat of solution heat of hydration 03
   • c) lattice energy 1i) How are these related to each other? How do they help in understanding 02 the solubilities of ionic compounds? B Give an account of the following: 05
   • i) Born Lande’s equation ii) Structure of CsCl C What are the important postulates of ‘Valence Bond Theory’? 05 D Predict the geometry and give an example for each one of the following 05
4. Q1 molecule with 1 lone pair of electrons
   • ii) AB4 molecule with 2 lone pairs of electrons
   • iii) orbitals E Draw a neat, labeled MO diagram for F2 molecule. Calculate its bond 05 order and mention its molecular configuration and magnetic property F Explain why mixing of orbitals takes place in case of and C2 molecules. 05 Give an account of the magnetic properties of B2 and C2 molecules on the basis of MOT
5. Q4 Attempt any four from the following—
   • (i) Give preparation of phenol from- 03
   • a) chlorobenzene Explain the effect of electron donating substituent on acidic character of 02 B What is cine substitution? Explain with mechanism. 05 What is the action of conc. on 03
   • (ii) Give preparation of ethylene oxide from 02 D~ Give preparation of phenyl magnesium bromide and what happens when 03 phenyl magnesium bromide reacts with
   • a) b) dry ice What is sulphation of alcohol? Give one example. 02 E What happens when- 05
   • a) cyclohexyl magnesium chloride reacts with ammonia
   • b) sodium phenoxide is heated with ethyl bromide in ethanol
   • c) ethylene oxide is heated with excess of water in presence of H2SQ4
   • d) phenol is treated with bromine water
   • e) 2-propanol is heated with 60% H2SOx at
   • f) ethyl lithium reacts with ethanol F (i) What happens when ethylene oxide reacts with 03
   • (ii) What is etherification of alcohol? Give one example. 02
6. Q5 Attempt any four from the following— B The value of molar conductance at infinite dilution of 1s 05 S while that of ions is 160 S cm?/mol. Calculate the molar conductance of Al** ion at infinite dilution C Explain the following
7. Q1 Equivalent and non-equivalent hybrid orbitals 3 marks
   • ii) Equatorial P— Cl bonds are shorter than the axial P— Cl bonds 02 in PCls molecule D Answer the following with reference to MOT 05
   • i) definition of molecular orbitals
   • ii) conditions for the formation of orbitals in di atomic
   • ii) formation of molecular orbitals with the help of diagrams E Explain the mechanism of alkaline hydrolysis of methyl bromide giving 05 F What happens when methyl lithium reacts with 05 iii) iv)

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