Benzene- Structure, Properties & Uses | Chemistry for JAMB PDF Download

Structure of Benzene

• Benzene (C₆H₆) is an organic compound composed of six carbon atoms arranged in a ring with alternating single and double bonds.
• Each carbon atom is bonded to a hydrogen atom, resulting in a total of six hydrogen atoms.
• The ring structure is planar and exhibits a high degree of stability due to the delocalization of electrons.

Properties of Benzene:

A. Physical Properties

1. Odor: Benzene has a characteristic sweet odor.
2. State: It is a colorless liquid at room temperature.
3. Density: The density of benzene is approximately 0.88 g/cm³.
4. Boiling Point: Benzene has a boiling point of 80.1°C.
5. Melting Point: The melting point of benzene is 5.5°C.
6. Solubility: It is slightly soluble in water but highly soluble in organic solvents like ether, alcohol, and chloroform.

B. Chemical Properties

1. Stability: Benzene is highly stable due to its resonance structure and exhibits low reactivity compared to other unsaturated hydrocarbons.
2. Combustion: It burns in the presence of oxygen to produce carbon dioxide and water, releasing a significant amount of heat.
3. Substitution Reactions: Benzene undergoes substitution reactions rather than addition reactions due to its stability.
4. Electrophilic Aromatic Substitution: Benzene is highly reactive towards electrophiles, which can replace one of the hydrogen atoms on the benzene ring.
5. Resonance Stabilization: The delocalization of pi electrons in the benzene ring gives it increased stability and prevents it from undergoing typical addition reactions.

Uses of Benzene

• Chemical Intermediates: Benzene is widely used as a starting material in the production of various chemicals, including plastics, dyes, detergents, and pharmaceuticals.
• Solvent: It serves as an effective solvent for many organic substances and is commonly used in industries such as paints, coatings, adhesives, and printing.
• Fuels: Benzene is a component of gasoline, where it acts as an octane booster, enhancing the efficiency of the fuel.
• Rubber and Plastics: Benzene is utilized in the manufacturing of synthetic rubber, such as styrene-butadiene rubber (SBR), and in the production of polymers like polystyrene and nylon.
• Pharmaceuticals: It is an essential building block in the synthesis of drugs, including analgesics, antiseptics, anesthetics, and antibiotics.
• Aromatic Compounds: Benzene is a fundamental aromatic compound and is used as a reference for aromaticity in organic chemistry.