IGNOU CHE-02
- Inorganic Chemistry,
Latest Solved Assignment
(January 2024 - December 2024)

1. a) Give the names of the chemists who discovered scandium and germanium.
b) Explain Pauli’s exclusion principle and Hund’s rule.
c) What is the difference between electron affinity and ionisation energy.

2. Explain the following:

a) Atomic size generally decreases across the period and increases down the group in the periodic table.
b) The difference between the 1st and the 2nd ionisation energy of Li is much higher than that of Be.
c) In Group 17, HF has abnormally high melting and boiling points as compared to other hydrides of the group.
d) Intermolecular hydrogen bonding does not take place in p-nitrophenol.
e) Physical properties of isotopes of hydrogen are different.

3. a) Give the structure of the following complex ions:

i) [BeF4]2-
ii) [Be(C2O4)2]2-

b) Give the reaction of aqua regia with gold.
c) Explain giving suitable reactions whether NaNH2 acts as an acid or a base in liquid ammonia.

4. a) Give the method of preparation of pure crystalline boron.
b) Why corundum finds many applications in abrasives, refractories and ceramics?
c) Explain the structure of diborane.

5. a) Explain the differences in structure and bonding in trimethylamine and trisilylamine.
b) Give the process of extraction of phosphorous.

6. a) What are the two allotropic forms of oxygen? Differentiate between them and write the method of preparation of each of these.
b) Explain why there is large difference in the melting and boiling points of oxygen and sulphur.

7. a) How did Moissan prepare fluorine? What are the modifications done to his method?

b) Describe the following in brief:

i) Basic properties of halogens
ii) Nature and stability of halogen oxides

8. a) What are clathrates? What is the criteria of formation of clathrates?
b) What is the significance of beneficiation of ores? List various methods used for the same.

9. a) What factors determine whether a complex is high spin or low spin?
b) Describe the difference between a high spin and a low spin d6 complex.
c) Explain which one of [Fe (H2O)6]2+ and [Fe(CN)6]4- complex ions is high spin and which one is low spin?

10. a) Chemical properties of the transition metals vary widely from element to element. In contrast, the inner-transition metals markedly resemble each other chemically. Explain.
b) All the lanthanide elements form generally stable compounds in +3 oxidation state. Then, why do cerium and europium form most stable compounds in + 4 and + 2 oxidation states, respectively?
c) Why do many transition metals exhibit a +2 oxidation state in their compounds?

1. a) Give the names of the chemists who discovered scandium and germanium
b) Explain Pauli’s exclusion principle and Hund’s rule.
c) What is the difference between electron affinity and ionisation energy.

2. Explain the following:
a) Atomic size generally decreases across the period and increases down the group in the periodic table.
b) The difference between the 1st and the 2nd ionisation energy of Li is much higher than that of Be.
c) In Group 17, HF has abnormally high melting and boiling points as compared to other hydrides of the group.
d) Intermolecular hydrogen bonding does not take place in p-nitrophenol.
e) Physical properties of isotopes of hydrogen are different.

3. a) Give the structure of the following complex ions:
i) [BeF4]2-
ii [Be(C2O4)2]2-
b) Give the reaction of aqua regia with gold.
c) Explain giving suitable reactions whether NaNH2 acts as an acid or a base in liquid ammonia.

4. a) Give the method of preparation of pure crystalline boron.
b) Why corundum finds many applications in abrasives, refractories and ceramics?
c) Explain the structure of diborane.

5. a) Explain the differences in structure and bonding in trimethylamine and trisilylamine.
b) Give the process of extraction of phosphorous.

6. a) What are the two allotropic forms of oxygen? Differentiate between them and write the method of preparation of each of these.
b) Explain why there is large difference in the melting and boiling points of oxygen and Sulphur.

7. a) How did Moissan prepare fluorine? What are the modifications done to his method?
b) Describe the following in brief:
i) Basic properties of halogens
ii) Nature and stability of halogen oxides

8. a) What are clathrates? What is the criteria of formation of clathrates?
b) What is the significance of beneficiation of ores? List various methods used for the same

9. i) What factors determine whether a complex is high spin or low spin?
ii) Describe the difference between a high spin and a low spin d6 complex.
iii) Explain which one of [Fe (H2O)6]2+ and [Fe(CN)6]4- complex ions is high spin and which one is low spin?

10. a) Chemical properties of the transition metals vary widely from element to element. In contrast, the inner-transition metals markedly resemble each other chemically. Explain.
b) All the lanthanide elements form generally stable compounds in +3 oxidation state. Then, why do cerium and europium form most stable compounds in + 4 and + 2 oxidation states, respectively?
c) Why do many transition metals exhibit a +2 oxidation state in their compounds?