Class 10 Science Chapter 4: Carbon and Its Compounds - Notes

🔰 Introduction

Carbon is a very important element. It is the basis of all living organisms and forms millions of compounds due to its unique bonding properties.

🧪 Why Carbon Forms So Many Compounds

• Catenation: Ability to form long chains with itself.

• Tetravalency: Carbon has 4 valence electrons → Forms 4 covalent bonds.

• Covalent Bonding: Shares electrons instead of donating/accepting.

🔗 Covalent Bond

• A covalent bond is formed by sharing of electrons.

• Types:

  • Single bond: e.g., H–H

  • Double bond: e.g., O=O

  • Triple bond: e.g., N≡N

🧬 Versatile Nature of Carbon

• Forms chains, branches, and rings.

• Combines with elements like H, O, N, Cl, etc.

• Forms saturated (single bond) and unsaturated (double/triple bond) compounds.

📊 Saturated and Unsaturated Compounds

🧪 Homologous Series

• A group of organic compounds with similar chemical properties.

• Same functional group.

• Formula differs by –CH₂– group.

• Example: Alkanes – CH₄, C₂H₆, C₃H₈...

🧬 Functional Groups

🧪 Chemical Properties of Carbon Compounds

1. Combustion:
   Carbon compound + O₂ → CO₂ + H₂O + heat

2. Oxidation:
   Alcohols can be oxidized to acids using oxidizing agents (e.g., KMnO₄)

3. Addition Reaction:
   Hydrogen is added to unsaturated compounds (in presence of catalyst like Ni).

4. Substitution Reaction:
   In saturated hydrocarbons, one hydrogen is replaced by another atom (like Cl).

🧼 Soaps and Detergents

• Soap: Sodium/potassium salt of fatty acid. Works in soft water.

• Detergents: Synthetic. Work even in hard water.

✅ Key Points to Remember

• Carbon is tetravalent – makes 4 covalent bonds.

• Forms a huge variety of compounds due to catenation.

• Understand homologous series and functional groups.

• Learn reactions: combustion, oxidation, addition, substitution.