University of Delhi 2006-2nd Year B.Sc Chemistry IV Inorganic Year : - Question Paper

Q. 1. discuss any 7 of the subsequent :
(i) Alkali metal salts impart a characteristic color to the flame.
(ii) The solubilities of sulphates of Group II reduce down the group.
(iii) BCI3 is monomeric whereas A1C13 is dimeric.
(iv) PbO2 is less stable than PbO.
(v) HF is a liquid whereas HCl is a gas at room temperature.
(vi) NC13 exists but NC15 does not,
(vii) Lithium carborate decomposes on heating,
(viii) Nitric oxide (NO) is paramagnetic,
(ix) Chlorine is a stronger oxidizing agent than iodine.

Q. 2. (a) Why does lithium form normal oxides, sodium forms peroxide and potassium, rubidium form superoxides ? 2
(b) BF3 and BrF3 molecules have various structures. discuss.
(c ) Why oxygen exists as O2 and sulphur as S8 ?

Q, 3. (a) define roasting. What is auto reduction ? 2
(b) Expain zone refining with diagram. 2
(c ) discuss acidic and basic flux with 1 example every as used in metallurgy.

Q. 4. (a) provide a method for preparing borax from the mineral colemanite. provide its 4 uses.
(b) provide a method of preparation of diborane. Why it is called an electron deficient compound. explain its structure. 3
(c ) provide the reaction of diborane with water and ammonia.

Q. 5. Write short notes on any 2 of the subsequent :
(i) Classification of silicates
(ii) Oxyacids of nitrogen
(iii) Pseudohalogens and pseudohalides.

Q. 6. (a) elaborate interhalogen compounds ? How does VSEPR theory discuss the structures of AX3, AX5 and AX7 types?
(b) How is hydrazine prepared by Raschig’s Method ? provide its structure.

Earning:   Approval pending.