chemistry Honours(H1) 1st sem 2013 previous year BSc question paper | Assam University

chemistry Honours 1st sem 2013 previous year BSc question paper | Assam University

TDC Odd Semester Examination, 2013 

CHEMISTRY 

Honours 

( 1st Semester ) 

Course No. : CHMH-1O1 

Inorganic Chemistry—I ) 

Full Marks: 35 

Pass Marks: 12 

Time: 2 hours 

The figures in the margin indicate full marks for the questions 

Answer five questions, taking one from each Unit 

UNIT—I 

1. (a) Write the modified energy expression of Bohr considering the motion of electron and nucleus. 2
(b) Explain essential differences between Photoelectric effect and Compton effect. 2
(c) Calculate (i) the wavelength of the lowest energy transition in Balmer series of the H spectrum and (ii) ionisation energy of H atom.

2. (a) Write down Heisenberg’s uncertainty principle and discuss its significance. 2
(b) Define eigenfunction and eigenvalue equations. Explain the physical significance of ψ.
(c) The speed of an electron is 1.2 x 106 m/sec. What is its de Brogue wavelength?

3. (a) Describe the Lande’s method of determining the ionic radius. 2
(b) Define ionisation potential. Mention different factors that govern the magnitude of ionisation potential.
(c) Interatomic distance in Cl2 is 1958 A. Calculate the A-R electronegativity of Cl using Slater’s rule.

4. (a) Give an account of usefulness of electronegativity in predicting (i) polarity of molecules and (ii) molecular association. 1 1/2x2=3
(b) Explain why the electron affinity (EA) of F is lower than that of Cl although the electronegativity (EN) of F is higher than that of Cl. 2
(c) “BF3 is nonpolar while NF3 is polar.” Comment.

UNIT—III

5. (a) What are rianomaterials? Write the measurable properties of nanomaterials.
(b) ClassiIy different types of nanomaterials and give examples for them.
(c) What are the challenges in synthesis of nanomaterials?

6. (a) With a sketch, explain the mechanical process for synthesis of nanoparticles. Write advantages and disadvantages of mechanical process.
(b) Explain gas phase synthesis of oxide nanoparticles. Mention any two applications of metal-oxide nanoparticles.

UNIT—IV 

7. (a) Furnish the structure of Br20 using VSEPR theory and hybridisation model. Compare Bi2O bond angle with F20. 3a
(b) “HOd is very weak acid but HC1O4 is extremely strong.” Justify the statement. 2
(c) Write with equation, the preparation of HNO2 and its reaction with aniline. 2

8. (a) How does Ar originate in air? Discuss the isolation of Ar from N2 /°2 mixture.
(b) Write with equation the preparation of oxides and fluorides of Xe (VI).
(c) “He(helium) has wide applications among noble gases.” Justify with examples.

UNIT—V 

9. (a) How is high alumina cement prepared? Write its typical composition. Give major advantages and disadvantages of high alumina cement over Portland cement.
(b) Discuss the preparation of ammonium subhate phosphate (ASP). Give its uses as fertilizer. 2+1=3

10. (a) Write with equations the preparation of urea from calcium cyanamide. Why calcium cyanamide is important compare to other nitrogenous fertilizers? 2+1=3
(b) Describe the preparation of Portland cement. 2
(c) Give the compositions of ammonium sulphate nitrate (ASN). How is ASN used as fertilizer? 2

14J—500/70 N-13/ODD/CHMH—1O1/245