Some Important Carbon Compounds Ethanol And Ethanoic Acid

Key Notes:

Introduction to Carbon Compounds

• Carbon compounds are molecules that contain carbon atoms bonded to other elements like hydrogen, oxygen, and nitrogen.
• Organic compounds are primarily carbon-based and include alcohols, acids, hydrocarbons, etc.

Ethanol (Ethyl Alcohol) – C₂H₅OH

• Structure: Ethanol has the molecular formula C₂H₅OH, with an -OH (hydroxyl) functional group attached to an ethyl group.
• Physical Properties:
  • A colorless, volatile liquid with a characteristic odor.
  • Soluble in water and has a boiling point of about 78.5^∘C.
• Chemical Properties:
  • Combustion: Ethanol burns in air to produce carbon dioxide and water.

C₂H₅OH+3O₂→2CO₂+3H₂O

• Reaction with Sodium: Produces sodium ethoxide and hydrogen gas.

2C₂H₅OH+2Na→2C₂H₅ONa+H₂

• Oxidation: Oxidizes to ethanoic acid (acetic acid) using oxidizing agents like potassium dichromate.
• Uses:
  • Used as a solvent, in alcoholic beverages, as a fuel (bioethanol), and in medicines.

Ethanoic Acid (Acetic Acid) – CH₃COOH

• Structure: Ethanoic acid has the molecular formula CH₃COOH, with a carboxyl (-COOH) functional group.
• Physical Properties:
  • A colorless liquid with a strong, pungent smell (like vinegar).
  • Miscible with water and has a boiling point of about 118^∘C.
• Chemical Properties:
  • Acidic Nature: Ethanoic acid is a weak acid and partially dissociates in water to release hydrogen ions.

CH₃COOH ⇌ CH₃COO⁻ + H⁺

• Reaction with Bases: Forms salts and water (neutralization reaction).

CH₃COOH + NaOH → CH₃COONa + H₂O

• Esterification: Reacts with alcohols in the presence of an acid catalyst to form esters.

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O

• Uses:
  • Used in the production of vinegar, synthetic fibers, and as a preservative in food.

Distinguishing Between Ethanol and Ethanoic Acid

• Litmus Test: Ethanoic acid turns blue litmus paper red, while ethanol does not affect litmus paper.
• Sodium Bicarbonate Test: Ethanoic acid reacts with sodium bicarbonate to release carbon dioxide gas, while ethanol does not.

Common Uses and Applications

• Ethanol: Biofuel, antiseptic, solvent in perfumes and cosmetics.
• Ethanoic Acid: Used in vinegar (5-8% solution), food preservation, and in the manufacture of synthetic materials.

Health and Safety Considerations

• Ethanol is flammable and should be handled with care.
• Ethanoic acid is corrosive; concentrated solutions can cause skin burns and damage to eyes.

Laboratory Preparation of Ethanoic Acid

• Ethanol can be oxidized to ethanoic acid using strong oxidizing agents like potassium permanganate (KMnO₄​).

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