Summary
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