91Ó°ÊÓ

Cyclopropane is a small three-membered ring with C-C-C bond angles of approximately 60°. This smaller ring structure results in significant angle strain and torsional strain, making such compounds reactive and unstable compared to five- and six-membered ring structures where C-C-C bond angles are closer to the more stable 109.5° (the ideal tetrahedral angle). The angle strain makes the C-C bond highly reactive, promoting reactions with electrophiles such as HI. On the other hand, cyclopentane and cyclohexane do not exhibit such high reactivity due to their lower angle and torsional strains.

Ethylbenzene can be prepared from benzene and ethylene via a Friedel Crafts alkylation reaction, which involves the electrophilic alkylation of benzene, using ethylene as the alkylating agent. To conduct this reaction, we will use anhydrous aluminum chloride (AlCl\(_3\)) as a catalytic Lewis acid to enhance the electrophilic nature of ethylene. Step-by-step procedure: 1. Mix benzene and ethylene in presence of anhydrous aluminum chloride (AlCl\(_3\)) as a catalyst. 2. The ethylene (C\(_2\)H\(_4\)) molecule reacts with the AlCl\(_3\) catalyst to form a high-energy complex, which makes the carbon in ethylene more electrophilic. 3. Benzene, being a nucleophile, reacts with the ethylene electrophile to form ethylbenzene (C\(_6\)H\(_5\)C\(_2\)H\(_5\)) and regeneration of the AlCl\(_3\) catalyst. 4. Separate the ethylbenzene product by simple or fractional distillation as it has different boiling points from benzene and other byproducts. In summary, the preparation of ethylbenzene can be achieved through the Friedel Crafts alkylation reaction of benzene and ethylene in the presence of an AlCl\(_3\) catalyst.