Class 10 Science Carbon and its Compounds Notes

Class 10 Science Carbon and its Compounds Notes

Introduction

  • Carbon is a non-metal with unique bonding properties.
  • Forms catenation (bonding with itself) and variety of compounds.
  • Forms organic compounds, mainly hydrocarbons and functional derivatives.

1. Covalent Bonding in Carbon

  • Carbon has 4 valence electrons → forms 4 covalent bonds.
  • Tetra-valency allows carbon to form chains, rings, and complex structures.

2. Versatile Nature of Carbon

  1. Catenation: Ability to form long chains (e.g., C₆H₁₄).
  2. Tetravalency: Forms four covalent bonds.
  3. Formation of stable compounds with hydrogen, oxygen, nitrogen, and halogens.

3. Hydrocarbons

Alkanes (Saturated Hydrocarbons)

  • Only single bonds (C–C, C–H)
  • General formula: CnH2n+2
  • Example: Methane (CH₄), Ethane (C₂H₆)

Alkenes (Unsaturated Hydrocarbons)

  • Double bonds (C=C)
  • General formula: CnH2n
  • Example: Ethene (C₂H₄)

Alkynes (Unsaturated Hydrocarbons)

  • Triple bonds (C≡C)
  • General formula: CnH2n−2
  • Example: Ethyne (C₂H₂)

Aromatic Hydrocarbons

  • Contain benzene ring (C₆H₆)
  • Example: Toluene, Phenol

4. Functional Groups in Carbon Compounds

Functional GroupGeneral FormulaExample
Alcohol–OHCH₃OH
Aldehyde–CHOHCHO
Ketone–CO–CH₃COCH₃
Carboxylic Acid–COOHCH₃COOH
Ester–COO–CH₃COOCH₃
Amine–NH₂CH₃NH₂

5. Important Reactions of Carbon Compounds

  1. Combustion: Hydrocarbon + O₂ → CO₂ + H₂O
    • Example: CH₄ + 2O₂ → CO₂ + 2H₂O
  2. Substitution: Hydrogen replaced by halogen (in alkanes)
    • Example: CH₄ + Cl₂ → CH₃Cl + HCl
  3. Addition: Unsaturated hydrocarbons react with H₂, Cl₂, or Br₂
    • Example: C₂H₄ + Br₂ → C₂H₄Br₂
  4. Esterification: Acid + alcohol → Ester + Water
    • Example: CH₃COOH + CH₃OH → CH₃COOCH₃ + H₂O

6. Uses of Carbon Compounds

  • Fuels: Coal, petrol, natural gas
  • Plastics: Polyethylene, PVC
  • Medicines: Aspirin, paracetamol
  • Synthetic fibers: Nylon, Polyester
  • Food: Carbohydrates, fats, proteins