Lecture Notes: Alkanes

Introduction to Alkanes

• Alkanes are saturated hydrocarbons.
• They consist entirely of single-bonded carbon and hydrogen atoms.

General Formula

• The general formula for alkanes is CₙH₂ₙ₊₂.

Properties of Alkanes

• Typically nonpolar.
• Insoluble in water.
• Have relatively low boiling points.

Structure

• Alkanes have a tetrahedral geometry around each carbon atom.

Isomers

• Structural isomers exist for alkanes with four or more carbon atoms.
• Isomers have the same molecular formula but different structural formulas.

Nomenclature

• Alkanes are named based on the number of carbon atoms they contain:
  • Methane: 1 carbon
  • Ethane: 2 carbons
  • Propane: 3 carbons
  • Butane: 4 carbons
  • Pentane: 5 carbons, etc.

Reactions

• Combustion: Alkanes react with oxygen to produce carbon dioxide and water.
• Substitution: Alkanes can undergo substitution reactions with halogens.

Uses of Alkanes

• Alkanes are commonly used as fuels (e.g., methane, propane, butane).
• Also used in the production of other chemicals.

Environmental Impact

• Burning alkanes releases CO2, a greenhouse gas contributing to climate change.

Conclusion

• Alkanes are a fundamental class of hydrocarbons with significant industrial and environmental relevance.