ChemNexa← All chapters
CHAPTER 9 • 8 MARKS

Organic Chemistry

Study carbon bonding, hydrocarbons, functional groups, homologous series and important organic reactions and compounds.

Topics in this chapter

  1. Unique nature of carbon
  2. Catenation and tetravalency
  3. Hydrocarbons
  4. Saturated and unsaturated compounds
  5. Homologous series
  6. Functional groups
  7. Basic nomenclature
  8. Ethanol and ethanoic acid
  9. Addition, substitution and oxidation reactions
  10. Polymers, soaps and detergents

Key learning points

✓ Carbon forms stable covalent bonds and long chains.

✓ A homologous series has the same functional group and general formula.

✓ Unsaturated hydrocarbons undergo addition reactions.

✓ Soaps form micelles; detergents work better in hard water.

Important equations and relations

CH₄ + 2O₂ → CO₂ + 2H₂OC₂H₄ + H₂ → C₂H₆C₂H₅OH + 2[O] → CH₃COOH + H₂OCH₃COOH + C₂H₅OH ⇌ CH₃COOC₂H₅ + H₂O

Multiple-choice questions

1. The functional group of alcohols is:
  1. –COOH
  2. –OH
  3. –CHO
  4. –NH₂

Answer: B — –OH

2. Ethene is:
  1. Saturated
  2. Unsaturated
  3. Ionic
  4. A metal

Answer: B — Unsaturated

3. Successive homologues differ by:
  1. CH₂
  2. CH₃
  3. OH
  4. CO₂

Answer: A — CH₂

Very short-answer questions

  1. Define catenation.
  2. What is a homologous series?
  3. Write the formula of ethanoic acid.

Short-answer questions

  1. Differentiate between saturated and unsaturated hydrocarbons.
  2. Explain cleansing action of soap.

Long-answer question

  1. Explain the versatile nature of carbon and important reactions of organic compounds with equations.