MCH-11 EM 2025-26 SOLVED ASSIGNMENT

Description

M.Sc. in Chemistry Programme (MSCCHEM)

Tutor Marked Assignment
MCH-011: INORGANIC CHEMISTRY 1
Course Code: MCH-011
Assignment Code: MCH-011/TMA/2025-26

Valid from 1st July, 2025 to 30th June, 202

1.a) Explain the trends of ionization energy down the groups of the elements in the periodic table. How are the higher values of ionisation energies of the 5d transition elements justified? (5)

b) What is the trend of the stability of the +6 state for Group 6 elements like tungsten, molybdenum and chromium? Which other group show a similar trend? Justify your answer. (5)

2.a) Explain the structure of the pentafluorotellurate(IV) anion with the help of VSEPR theory. What is the point group of the symmetry in it? (5)

b) With suitable illustration explain the theory of Dewar for π bonding in phosphazenes. What is phospham and how it is synthesized? Give suitable reaction. (5)

3.a) Give the classification of nonclassically bonded organometallic compounds. (5)

b) With any two suitable examples show how organanometallic complexes of different classes may be stabilized by bulky ligands. (5)

4.a) With suitable illustration explain the bent tin-tin double bond in (SnR2 )2 ; where R = (Me3 Si)2 CH. (5)

b) With the help of suitable examples and structures, explain why some of the 16-electron organometallic complexes are stable. For a d8 metal ion which form will be more stable, 16 electron square planar complex (d8 and 8 ligand electrons) or a 18-electron complex (d8 and 10 ligand electrons)? Justify your answer. (5)

5.a) With suitable diagrams explain the electronic structure of NO and its binding to a metal fragment on the covalent model. (5)

b) Compare the characteristics of electron-rich phosphines with those of electron poor phosphines regarding their s donor and p acceptor capacities. What happens to these characteristics when the average electronegativity of the three groups attached to P increases? (5)

6.a) Explain the p system of the allyl group with the help of molecular orbital theory. Illustrate your answer. (5)

b) Give the structure of titanocene with its IUPAC nomenclature. How is the Hund’s rule obeyed in manganocene? (5)

7.a) Give the reactions for preparation of decaborane(14) from B5 H8- anion. Which is the only neutral dodecaborane and how is it prepared? Give suitable equation. (5)

b) Explain the structure of Mo6 Cl8 2- . Which are the two main classes of metal atom cluster  compounds?

8.a)) Give the electronic configuration of d4 and d7complexes in both weak and strong fields. Also calculate their CFSE.

b)Explain the structure of normal spinels with a suitable example. Give suitable illustration.

9.a)  Give suitable equations and explain the orbital and spin contributions towards paramagnetism in a complex.

b) What is the expected magnetic moment of the complex MnF3 ? What sort of stereochemistry is seen in it? What is the electron configuration in it based on crystal field theory.

10.a) Write the Russell-Saunders terms symbols for states with the angular momentum quantum numbers (L,S) (a) (1, 1/2) (b) (2,1) (c) (0, 3/2) (d) (3, 0).

b) Explain how the R- and S- labels are used for enantiomers. Explain the l and d conformations of methyl axial and methyl equatorial respectively. Give suitable illustrations for all of these.