Benzene II ELS Thomas Jefferson BenzeneC 6 H

Benzene II ELS „Thomas Jefferson“

Benzene(C 6 H 6) • Composition and Structure • A. Classical Concepts • B. Modern Concepts

Molecula

Classical Concepts • Working formula proposed by Kekule(1865) • Benzene does not decolorize solution of KMn. O 4

Modern Concepts • All the atoms are situated in one plain • The Carbon atoms form a regular hexagon. The valency angle is 120º • The shared electron pairs are located between the atoms the form the bonds

Physical Properties • • • Colorless Mobile liquid With a characteristic odor Insoluble in water Lighter then water Poisonous

Chemical Properties • A. Substitution reaction • B. Addition reaction • C. Combustion

A. Substitution Reaction • 1. Halogenation • C 6 H 6+Br 2 C 6 H 5 Br + HBr • Benzene bromobenzene

A. Substitution reaction • 2. Nitration with nitric acid (HNO 3) • C 6 H 6 + HNO 3 C 6 H 5 NO 2 + H 2 O • Benzene nitrobenzene

B. Addition Reaction • 1. Hydrogenation • C 6 H 6 + 3 H 2 C 6 H 12 + • benzene cyclohexane

Combustion • Benzene burns with a sooty flame • 2 C 6 H 6 + 15 O 2 12 CO 2 + 6 H 2 O

Uses • For the production of medical preparation, dyes, nitrobenzene • As a solvent

References • Binev, I. , et al. Chemistry for the 9 th class. Prosveta: Sofia, 1993 • Bliznakov, G. , et al. Chemistry and Environmental for the 9 th grade. Anubis: Sofia, 2002