Main Group Clusters: Basics and Applications — DU B.Sc (hons) Chemistry Previous Year Question Papers

4. The questions should be numbered in accordance with the number in the question paper. Q1. (a) Define the clusters in elemental state. Classify them on the basis of element type with examples. (b) What are carboranes? How are they classified? Give examples. (c) Draw the structures of isomers of CzB1oH12. (5,5,5) Q2. (a) Classify the following clusters as closo, nido, arachno, hypho, and klado: (b) What are Wade-Mingos rules? Illustrate giving examples. Complete and balance the followingreactions: Q3. (a) Define the terms S, T, Y, and X in STYX code. Draw the structures of the following boranes using STYX code: (b) Calculate the number of skeletal electrons in the following boranes and carboranes: (c) How does Jemmis rule differ from Wade rules? (5,5,5) Q4. (a) What are metallic clusters? How are they classified on the basis of applications? (b) Define Jemmis electron counting rule. Discuss the stabilities of the following clusters using Jemmis rule: (c) Discuss the structure of Bato. What will be the product when it reacts with MesN? (5,5,5) O5. (a) Define closo, nido, and arachno cluster. How are they related to each other? following STYX numbers (iii) BaH1z (c) What are heteroboranes ? Are carboranes heteroboranes? Q6. Write short notes on the following: (a) Boron Carbide (b) Metal Borides (c) Applications of Molecular Clusters (5,5,5)