Organic Chemistry: Hydrocarbons and Alkanes

Introduction to Organic Chemistry

• Organic chemistry focuses on compounds containing carbon.
• Carbon is essential for making large compounds due to its ability to form four strong bonds.
• Common bonding atoms with carbon include:
  • Other carbon atoms
  • Hydrogen atoms

Hydrocarbons

• Definition: Compounds formed only from carbon and hydrogen.
• Example of Hydrocarbon:
  • Butane: Contains only carbon and hydrogen.
• Non-example:
  • Butanol: Contains an oxygen atom, thus not a hydrocarbon.

Alkanes: The Simple Hydrocarbons

• Alkanes are the simplest type of hydrocarbons.
• First four alkanes in the series:
  1. Methane (CH₄): One carbon atom, four hydrogen atoms.
  2. Ethane (C₂H₆): Two carbon atoms, six hydrogen atoms.
  3. Propane (C₃H₈): Three carbon atoms, eight hydrogen atoms.
  4. Butane (C₄H₁₀): Four carbon atoms, ten hydrogen atoms.
• Homologous Series:
  • Alkanes grow by adding one carbon and two hydrogen atoms each time.
  • Series have similar properties and reactions.
  • General formula: CₙH₂ₙ₊₂
    • Example: Propane (C₃H₈) where n=3, so 23 + 2 = 8 hydrogens.

Calculating Molecular Formulas

• Use the general alkane formula to find larger molecular formulas.
• Example: Octane
  • Contains 8 carbon atoms (n=8).
  • Formula: C₈H₁₈ (28 + 2 = 18 hydrogen atoms).

Characteristics of Alkanes

• Saturated Compounds:
  • Every carbon has four single covalent bonds.
  • No double bonds present.
• Alkenes vs. Alkanes:
  • Alkenes have double bonds and are explored in cracking hydrocarbons.

Future Topics

• Next discussion: Properties of alkanes and combustion equation writing.

Conclusion

• Understanding alkanes lays the foundation for exploring further into hydrocarbons.
• Stay tuned for upcoming content on hydrocarbon properties and reactions.