chemistry Honours(H1) 3rd sem 2014 previous year BSc question paper | Assam University

chemistry Honours(H1) 3rd sem 2014 previous year BSc question paper | Assam University

TDC Odd Semester Exam., 2014 

CHEMISTRY 

(Honours) 

( 3rd Semester ) 

Paper No. : CHMH-301 

Inorganic Chemistry—Ill 

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) What are inner metallic complexes of first and second orders? Give examples. 2
(b) Illustrate with examples, the stabilization of uncommon oxidation states by complex formation of two metals of first transition series. 3
(c) Draw structures and indicate types of isomer formed by complexes of the formula [ML3X3].

2. (a) Discuss two factors that influence complex formation. 3
(b) Illustrate with a suitable example, how conductance change principle help in detection of complex formation in solution.
(c) Write the IUPAC names following :
(i) [CoC12(NH3)2(0H2)2]C1,
(iii) (NH4)2[Pt(SCN)oI
(iv) ICo(NH3)61[Cr(C204)31

UNIT—II 

3. (a) How is manganese extracted from its most important ore?

(b) Lanthanum exhibits +3 oxidation state whereas certain other elements of lanthanum series show +2 and +4 also. Explain.

(c) Comment on the colour of scandium(II1) ion.

(a)
4. (a) Give an account lor the colour exhibited by compounds O lanthanum series. 3
(b) How can chrome alum be prepared in the laboratory? 2
(c) How is scandium series different from lanthanum series in respect of complex formation? 2

UNIT—III 

5. (a) Briefly describe different considerations that contribute to valence bond approach in explaining the formation of chemical bond i H2 molecule. 4
(b) Illustrate with examples, how molecules with same number of valence shell electron pairs Caj have regular as well as distorted geometries. 3

6. (a) Describe the interactions which contribute to Vander Waals’ forces. 3
(b) Draw potential energy curve for H2 molecule and interpret its different sections. 2
(c) Carbon—oxygen bond lengths in CO are all equal atid intermediate between C—O and C 0 bond lengths. Explain. 2

UNIT—IV 

7. (a) Give one method of preparation for each of Caro’s acid and Marshall’s acid.
(b) Apply band theory to explain conductor and semiconductor behavior. 4

8. (a) Comment on insulator behavior in the light of electron sea model. 3
(b) What are different types of inter halogen compounds? Give examples.
(c) How can Caro’s acid and Marshall’s acid be distinguished from each other? 2

UNIT—V 

9. (a) Write two general methods of preparation of metal carbonyl. 3
(1) Define chelate effect and trans effect with suitable examples. 2+2=4

10. (a) Discuss Pearson’s ‘hard-hard soft-soft’ rule. 3
(b) Describe the bonding structure in metal carbonyl. In what respects, bonding in metal nitrosyl is different from that in metal carbonyl? 3+1=4