9
CBSE Marks
★★★★★
Difficulty
10
Topics
Very High
Board Weight
Topics Covered
10 key topics in this chapter
Covalent Bonding
Allotropes of Carbon
Versatile Nature of Carbon
Homologous Series
Nomenclature of Carbon Compounds
Functional Groups
Properties of Ethanol & Ethanoic Acid
Soaps and Detergents
Saponification
Cleansing Action of Soap
Study Resources
Key Formulas & Reactions
| Formula / Reaction / Rule | Expression |
|---|---|
| Alkane General | \(CₙH₂ₙ₊₂\) |
| Alkene General | \(CₙH₂ₙ\) |
| Alkyne General | \(CₙH₂ₙ₋₂\) |
| Combustion (ethanol) | \(C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O\) |
| Esterification | \(CH₃COOH + C₂H₅OH ⇌ CH₃COOC₂H₅ + H₂O\) |
| Saponification | \(Fat/Oil + NaOH → Soap (sodium salt) + Glycerol\) |
| Ethanoic acid + NaHCO₃ | \(CH₃COOH + NaHCO₃ → CH₃COONa + H₂O + CO₂\) |
Important Points to Remember
Carbon has 4 valence electrons allowing covalent bonding; it can form chains, branches and rings — called catenation.
Homologous series: each member differs by –CH₂– and 14 mass units. Alkane (CₙH₂ₙ₊₂), Alkene (CₙH₂ₙ), Alkyne (CₙH₂ₙ₋₂).
Ethanol (C₂H₅OH) is used as fuel, solvent, medicine. Ethanoic acid (CH₃COOH) is the acid in vinegar — reacts with NaHCO₃ to give CO₂.
Soaps work because they have a hydrophilic (ionic) head and hydrophobic (non-polar) tail — forming micelles around grease.