B.Sc. 1st Part Chemistry Honours Guess Questions Exam-2021
B.Sc. Chemistry Honours, Paper – I
Attempt five questions, selecting two from Group A and three from Group B.Group-A
1. (a) Describe the deviation of real gases from ideal gas behaviour.
(b) State Vander Waal equation and explain the significance of Vander Waal Constants.
(c) What is Boyle's Temperature.
2. (a) What do you mean by vapour pressure of a liquid. Give a method for its deterinination.
(b) Explain the term 'Parachor'. Discuss its utility in the elucidation of structure of molecules.
3. (a) Define
(i) No. of phases
(ii) Degree of freedom.
(iii) Number of component with suitable example.
(b) State and explain 'Phase rule' with examples.
4. (a) Explain any two of the following:
(1) Kohlrausch's Law
(ii) Cell Constant
(iii) Specific conductance.
(b) The molar conductivities of NaCl, HCl and sodium acetate are 126.4, 425.9 and 91.0 S cm2 mol-1 respectively at infinite dilution. Calculate the molar conductance of CH3COOH at infinite dilution.
Group-B
5. (a) Give the difference in the structure of diamond and graphite.
(b) Describe the structure of fullerenes.
(c) Why CO2 is gas but SiO2 is solid at room temperature.
6. (a) Name all the alkaline earth metals and write down their atomic no. and electronic confifuration.
(b) How will you account for any three of the following:
(i) KOH is a stronger base than Ba(OH)2
(ii) Lattice energy varies as Li F> Na F> KF > Rb F > Cs F.
(iii) The conductivity of Li+ in aqueous solution is less than that of Cs+.
(iv) Na gives golden yellow colour in flame.
7. (a) Draw molecular orbital energy level diagram for O2 molecule.
(b) Arrange the following in order of increasing bond length:
O2+, O2, O2− and O2−2
(c) What is the difference between σ and π bond.
(a) Explain any two of the following:
(i) Oxyacids of phosphorus
(ii) Inert pair effect
(iii) Inter halogen compounds.
(b) Give the hybridisation, structure and shape of PCl3 and PCl5.
9. (a) Identify the group and period of the following elements in the periodic table Mg(12), Sn(50), Ag(79), Ce(58) to which block of the periodic table, they belong.
(b) Which among Ti(22), V(23), Cr(24) and Mn(25) has the maximum second ionisation energy.
(c) Define electronegativity.
B.Sc. Chemistry Honours, Paper – II
Answer five question in all, selecting two from Group A and three from Group B. Group-A1. (a) Find out an expression for the work done in isothermal reversible expansion.
(b) What do you mean by limiting radius ratio. Calculate it for coordination number six.
2. (a) What do you mean by
(i) Bravias Lattices
(ii) Miller Indices.
(b) Discuss the crystal structure of CsCl.
3. (a) Explain
(i) Exothermic and Endothermic reaction
(ii) Internal Energy and Enthalpy.
(b) Prove that Cp - Cv = R for an ideal gas
4. (a) Discuss (i) De Broglie hypothesis
(ii) Heisenberg uncertainty principle.
(b) Calculate the wave length associated with an electron (m=9.11*10-288) travelling with a velocity of 50% of the velocity of light.
Group-B
5. (a) How will you prepare acetamide.
(b) How acetamide reacts with the following:
(i) aq. NaOH (ii) NaNO2 + HCl
(iii) Br2 and NaOH
(c) Why acetamide is a weaker base than NH3.
6. (a) Explain inductive effect. How it is different from electrometric effect
(b) Indicate the type of hybridisation of each carbon atom in the following:
H3C-C≡C-CH3, CH3CHO, C6H6
(c) Why C-C bond length in C2H6 and C2H4 are different.
7. (a) How will you identify the following elements in organic compound.
(i) CI
(ii) S
(iii) N and S both
(b) How will you determine the molecular mass of an organic base by chloroplatinate method.
(c) What do you mean by a free radical.
8. (a) How will you prepare Grignard reagent.
(b) Discuss the preparation of primary, secondary and tertiary alcohol with the help of Grignard reagent.
(c) What happens when propyne is treated with methyl magnesium iodide.
9. (a) Illustrate the following type of reactions by giving at least two suitable example.
(i) Addition reaction
(ii) Substitution reaction
(iii) Elimination reaction.
(b) Why the boiling point of ethyl alcohol is greater than diethyl ether.
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