Study Notes
Alkanes are saturated hydrocarbons that contain only single covalent bonds and are generally unreactive except in combustion and substitution reactions.
- Saturated Hydrocarbons — hydrocarbons with only single bonds between carbon atoms Example: Methane (CH₄) is a simple alkane.
- Complete Combustion — a reaction where hydrocarbons burn in oxygen to produce carbon dioxide and water Example: CH₄ + 2O₂ → CO₂ + 2H₂O
- Substitution Reaction — a chemical reaction where one atom is replaced by another Example: Methane reacts with chlorine in sunlight to form chloromethane.
Exam Tips
Key Definitions to Remember
- Saturated Hydrocarbons: Hydrocarbons with only single bonds.
- Complete Combustion: Hydrocarbons burning in oxygen to produce CO₂ and H₂O.
- Substitution Reaction: One atom is swapped with another.
Common Confusions
- Confusing saturated with unsaturated hydrocarbons.
- Misunderstanding the products of complete combustion.
Typical Exam Questions
- What are the products of complete combustion of methane? Carbon dioxide and water
- What happens in a substitution reaction with halogens? A hydrogen atom is replaced with a halogen atom
- How do alkanes react with chlorine? Through a substitution reaction in the presence of ultraviolet light
What Examiners Usually Test
- Understanding of the properties and reactions of alkanes
- Ability to write balanced equations for combustion and substitution reactions