PROPERTIES OF ETHANOL AND ETHANOIC ACID (CBSE 10TH CHEMISTRY IMPORTANT QUESTIONS)

 

Ethanol (C₂H₅OH)

Physical Properties:

• It is a colorless liquid with a pleasant smell.

• Soluble in water in all proportions.

• Boiling point ≈ 78°C.

Chemical Properties:

a) Combustion (Burning):

Ethanol burns in air to produce carbon dioxide and water.

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O  

Exothermic reaction – releases heat and light.

b) Reaction with Sodium:

Ethanol reacts with sodium metal to form sodium ethoxide and hydrogen gas.

2C₂H₅OH + 2Na → 2C₂H₅ONa + H₂↑

c) Dehydration (with Conc. H₂SO₄):

Ethanol can be dehydrated to form ethene in the presence of concentrated sulfuric acid.

C₂H₅OH  →  C₂H₄ + H₂O  

  (Conc. H₂SO₄, heat)

Ethanoic Acid (CH₃COOH)

Physical Properties:

• Also known as acetic acid.

• Has a sour taste and pungent smell.

• Freezes to form ice-like crystals below 16.7°C – called glacial acetic acid.

2. Chemical Properties:

a) Reaction with Metals (e.g., Zinc):

Forms a salt (zinc acetate) and hydrogen gas.

2CH₃COOH + Zn → (CH₃COO)₂Zn + H₂↑

b) Reaction with Carbonates/Bicarbonates:

Reacts to form a salt, water, and carbon dioxide gas.

CH₃COOH + NaHCO₃ → CH₃COONa + H₂O + CO₂↑

c) Esterification Reaction (with Alcohols):

Reacts with ethanol to form an ester (ethyl ethanoate) and water (in presence of acid catalyst).

CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O  
             (Conc. H₂SO₄)