Quick answer: Alkanes are saturated hydrocarbons containing only carbon–carbon and carbon–hydrogen single bonds. They show chain isomerism from butane onward. Common preparation methods include hydrogenation, decarboxylation, the Wurtz reaction and reduction of alkyl halides. Their main reactions are combustion, free-radical substitution and controlled oxidation.
What you will learn
- Structure and nomenclature of alkanes
- Chain isomerism and structural formulae
- Important laboratory preparation methods
- Physical properties and trends
- Combustion and free-radical substitution reactions
Important questions answered
What are alkanes?
Alkanes are saturated open-chain hydrocarbons with the general formula CnH2n+2.
When do alkanes show chain isomerism?
Chain isomerism begins with butane because four carbon atoms can be connected in more than one carbon skeleton.
What is the Wurtz reaction?
Two alkyl halide molecules react with sodium metal in dry ether to form a higher alkane.
Why are alkanes relatively unreactive?
Their C–C and C–H sigma bonds are strong and almost non-polar.
Who should use this lesson?
This lesson is useful for school students, competitive-exam aspirants, parents supporting a learner and teachers looking for a clear explanation. Watch the complete video, make short notes and then practise the ideas without looking at the solution.
Learn with Lalit Kumar Mishra
Lalit Kumar Mishra is a chemistry educator, student success mentor, author and Founder of Topper Formula, with more than 20 years of teaching experience. Explore more learning and mentoring resources on the Resources page.