Study Notes
Alkanes are the simplest family in organic chemistry, known as saturated hydrocarbons with only single covalent bonds. They are generally unreactive but undergo combustion and substitution reactions with halogens.
- Alkanes — hydrocarbons with single covalent bonds Example: Methane (CH4) is an alkane.
- Saturated Hydrocarbons — compounds with only single bonds Example: Propane (C3H8) is a saturated hydrocarbon.
- Combustion — a reaction where hydrocarbons burn in air to produce carbon dioxide and water Example: Complete combustion of methane produces CO2 and H2O.
- Substitution Reaction — a reaction where one atom is replaced by another Example: Methane reacts with chlorine in UV light to form chloromethane.
Exam Tips
Key Definitions to Remember
- Alkanes are saturated hydrocarbons with single covalent bonds.
- Substitution reactions involve replacing one atom with another.
Common Confusions
- Alkanes are often confused with alkenes, which have double bonds.
- Students may mix up complete and incomplete combustion products.
Typical Exam Questions
- What are the products of complete combustion of alkanes? Carbon dioxide and water
- How do alkanes react with halogens? Through substitution reactions in the presence of UV light
- What is the general formula for alkanes? CnH2n+2
What Examiners Usually Test
- Understanding of the properties and reactions of alkanes
- Ability to write and balance chemical equations for combustion and substitution
- Knowledge of the conditions required for substitution reactions