BSc Biochemistry Sem III 2018 2019 2019 Biochem Chemistry 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 (attempt any twelve)
   • (i) Gibss free energy is and a state function
   • a) an intensive property b) an extensive property
   • c) colligative property
   • (ii) Helmholtz free energy (A) in any process at constant temperature gives the maximum work done by the system
   • a) increase in the b) decrease in the c) constant
   • (iii) The variation of equilibrium constant with temperature is
   • (iv) Specific conductance of a solution is the conductance offered by unit
   • (v) Partial molal property is applicable to
   • (vi) The SI unit for conductivity cell constant
   • a) cm? c)em!
   • (vii) Crystal structure of
   • (viii) In anionic crystal cations and anions are held together by
   • (ix) In the formation of a molecule by an atom operate c) both attractive and repulsive forces operate
   • (x) Bond angle ina molecule adopting a trigonal planar geometry is
   • (xi) Elements with larger electronegativity difference combine to form (xil) The bond order in is
   • (xiv) Action of sodamide in liq.ammonia on p-bromo toluene gives
   • c) mixture of p-amino toluene and m-amino toluene
   • (xv) Organolithium compound reacts with alcohol to form
   • (xvi) Allyl aryl ethers on heating at about C undergoes rearrangement reaction known as
   • c) Kolbe’s reaction is a Grignard reagent
   • c) Diethyl zinc (xviii) on treatment with ------------- gives epoxide B State whether the following sentences are True or False 03 (attempt any three)
   • (i) Fugacity is a measure of escaping tendency for an ideal gases
   • (ii) In electrolytic solution, the current is carried by electrons
   • (iii) Molecular orbitals are polycentric
   • (iv) N2 molecule is paramagnetic in nature
   • (vi) Isobutyl alcohol is a secondary alcohol C Match the following (attempt any five) 05 Attempt any four from the following— A Explain the terms. - 05 B Derive thermodynamic expression for Van’t Hoff’s reaction isotherm. 05 C The free energy change (AG) for a particular process is -140.5 kJ mol"! at 05 K and - 137.5 kJ mol" at 313K. Calculate the enthalpy change (AH) for the D Explain the variation of molar conductance of an electrolyte with the 05 E Describe “moving boundary method’ for the determination of transport 05 F When the conductance of 0.5M solution is measured with the help of a 05 conductivity cell in which the electrodes are 1.2 cm apart having an area of cross section 1.1 cm* found to be 4 x Calculate molar conductance of the solution Attempt any four from the following— A 1) Differentiate between the terms lattice energy and heat of solvation. 02
   • ii) What is Kapustinsk1i’s equation? Using this equation, calculate the lattice 03 energy of KCI with the help of following data radius of K* = 138 pm; radius of pm; constant C = 1.079 x B 1) Discuss the structure of NaCl with the help of diagram. 03
   • ii) radii of and S* are 0.6A and 1.84A respectively. Predict the 02 coordination number of and the crystal structure of ZnS C Write notes on 05
3. Q1 resonance ii) sigma and pi covalent bonds D 1) Mention the theoretical and experimental bond energy and bond lengths 02 for the hydrogen molecule
   • ii) Explain the first improvement applied on the wave function of the 03 hydrogen system to bring the theoretical values of bond energy and bond length closer to the experimental values E i) Draw a neat labelled molecular orbital energy level diagram for N2 05 molecule and give it’s molecular electronic configuration. Comment on it’s bond order and magnetic property F 1) Discuss the conditions required for the formation of molecular orbitals. 02 Explain the representation of bonding and anti-bonding molecular 03 orbitals on the basis of wave function
4. Q4 Attempt any four from the following— A 1) Distinguish between Sn1 and reactions. 03 What is Grignard’s reagent? Give its preparation. 02 What is etherification and sulphation of alcohols? Give one example each. 03
   • a) p-nitro phenol is more acidic than phenol
   • b) o-nitro phenol is steam volatile whereas p-nitro phenol is not C Give preparation of phenyl lithium and what happens when phenyl lithium 05 D What are primary, secondary and tertiary alcohols? Give one method of 05 preparation of each of them E Give preparation of phenol from 03
   • a) chloro benzene by Dow’s process li) What happens when phenol reacts with 02
   • a) dil HNO3 b) excess of bromine water at room temp Fi) Give preparation of ethylene oxide from 03 li) How will you prepare following compounds from ethylene oxide. 02
5. Q5 Attempt any four from the following— A Explain the variation of chemical potential with pressure and temperature. 05 B The molar conductance of KBr at infinite dilution is 1.52 x 107 S mol! 05 and the transport number of K* is 0.48. Calculate the ionic mobility of the cation at infinite dilution of KBr at 298 K C Explain the following with the help of diagrams. 05
   • i) geometry of BrF3 molecule hybrid orbitals D a) Write a note on gerade and ungerade orbitals. 03
   • b) ‘Hydrogen exists as diatomic molecule but Helium does not’. Justifyon 02 the basis of MOT E What is Cine substitution; explain with mechanism. 05 F What happens when- 05
6. Q1 Phenol is treated with benzoyl chloride li) Sodium phenoxide is heated with ethyl bromide in ethanol ili) lithium reacts with acetaldehyde followed by hydrolysis
   • iv) Ethylene oxide reacts with HCN
   • v) Phenyl magnesium bromide is treated with phenyl cyanide followed by

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