IGNOU BCHCT-135
- Solutions, Phase equilibrium, Conductance, Electrochemistry and Functional Group Organic Chemistry-II,
Latest Solved Assignment
(January 2024 - December 2024)

PART-(A)

1. Discuss the fractional distillation for a mixture of benzene and toluene using a suitable diagram.

2. (a) Give the thermodynamic derivation of distribution law.
(b) Write any two applications of solvent extraction.

3. (a)Derive the expression for distribution coefficient when the solute dissociates is one of the solvents.
(b) Differentiate between true, metastable and unstable equilibria giving suitable examples.

4. (a) State Gibbs phase rule and give its mathematical form.
(b) How many components are there in the following systems? Briefly discuss.

5. (a) Calculate the maximum number of phases and maximum number of degrees of freedom that
(b) Can exist for a one-component system. When is a system called invariant? Illustrate with an example.

6. Draw and explain the phase diagram of sulphur

7. (a) Define conductivity. Give its SI units.
(b) List various factors on which the conductivity of electrolytic solutions depends.

8. Draw and explain the conductometric titration curves for the titration of the following:
(i) HCl vs NaOH
(ii) CH3COOH vs NaOH

9. (a) List the functions of a salt bridge.
(b) What are the conditions which a reversible cell should satisfy.

10. (a) What is an electrolyte concentration cell? Write the expression for Ecell for such a cell.
(b) Write the reactions occurring at electrodes in the electrolysis of water. Why are a few drops of conc. H2SO4 added in this process?

PART-(B)

11. Discuss the two methods of decarboxylation of carboxylic acids and comment on the nature of products formed.

12. How can you propane the following compound starting from ethanoyl chloride?

13. Briefly explain Hofmann elimination. Also give the importance of this reaction.

14. Differentiate between Sandmeyer reaction and Gattermann reaction giving suitable examples.

15. Discuss the Hinsberg test for distinguishing primary, secondary and tertiary amines.

16. (a) Discuss the preparation of 2-aminobutanoic acid using Strecker synthesis.
(b) What is cope elimination? Give reaction.

17. (a) Briefly explain this general structure and classification of peptides.
(b) What is bradykinin? Give its role?

18. How is C-terminal indentified in a peptide or a protein? Discuss.

19. (a) Explain the cyctic hemiacetal formation by glucose.
(b) Explain mutarotation in glucose.

20. Discuss the important features of structure of cellulose giving suitable diagram.

PART-(A)

1. (a) What are ideal solutions? Give two examples of such solutions.
(b) Draw and explain the vapour pressure curves for an ideal solution.

2. Draw and explain the mutual solubility curve for the phenol-water system.

3. (a) How do the impurities Affect the CST values? Explain.
(b) Explain the stability of different phases of a pure substance in terms of chemical potential versus temperature curves.

4. Define any five of the following terms:

(i) Phase
(ii) Azeotropes
(iii) Congruent melting
(iv) Concentration cell
(v) Conductometric titration
(vi) Galvanic cells

5. (a) What is the criterion for phase equilibrium for a heterogeneous system at constant pressure and temperature?
(b) Define components in the context of phase rule. Calculate the number of components for the sublimation equilibrium of NH4Cl assuming that NH3 (g) and HCl (g) are produced from the sublimation of NH4Cl (s) only.

6. (a) What is the triple point for a one component system? What is the degrees of freedom at the triple point?
(b) Draw and explain the phase diagram for a simple eutectic system and give an industrial application for the same.

7. (a) Define molar conductivity and give its significance.
(b) In a conductivity cell, the two platinum electrodes, each having an area of 2 cm 2 are 1 cm apart. Using this cell the resistance of a 0.1 M solution of acetic acid is found to be 470Ω. Calculate the molar conductivity of the solution.

8. (a) List the requirements for an electrolyte to be indicator electrolyte in the moving boundary method for the determination of transference numbers’
(b) In the determination of transference numbers of HCl by moving boundary method a 0.10 M solution of HCl was taken in a cell having uniform area of cross section of 1.0 cm2. At the end of experiment the boundary moved by 10.3 cm and 0.132 g of silver was deposited on the cathode of silver coulometer. Calculate the transference numbers of ions of HCl.

9. (a) Differentiate between reversible and irreversible cells.
(b)Write the cell diagram for a galvanic cell in which the following reaction takes place.

Assume that potassium nitrate is used as electrolyte in the salt bridge and the concentrations of tin ions and silver ions are c1 and c2 respectively.

10. (a) Define electrolysis. Name the gases evolved in the electrolysis of brine.
(b) Define liquid junction potential and describe its development.

PART-(B)

11. Discuss the mechanism of Hell-Vohlard-Zelinsky reaction.

12. Write the mechanism and the products formed for the following reactions:

13. (a) Give the IUPAC names of the following compounds:

(b) Briefly explain the following reactions:
(i) Hofmann rearrangement
(ii) Schmidt rearrangement

14. (a) How will you prepare the following compounds? Give reactions.
(i) 4-methylbiphenyl
(ii) 4-hydroxyazobenzene
(iii) butter yellow dye
(b) How will you convert 4-bronobenzenmine to 4-bromobenzenol?

15. (a) Discuss the nitrosation reaction of primary amines.
(b) Discuss the nitration reaction of aniline. How would you account for the formation of different products?

16. (a) What is electrophoresis? Briefly explain. Also give its importance.
(b) What BOC-group? Which reagent is used to introduce this group?

17. How will you synthesise valine using Gabriel phthalimide synthesis?

18. Discuss the secondary structure of peptides.

19. (a) Briefly explain the phenyl osazone formation by monosaccharides.
(b) Why do D-(+)-glucose and D-(+)-mannose give the same osazone?

20. (a) What are polysaccharides? Give examples.
(b) Briefly explain the structure aspects of starch.