Alkenes and Their Properties
Alkenes are unsaturated hydrocarbons that contain a carbon-carbon double bond , which makes them much more reactive than alkanes. The first four alkenes you need to know are ethene, propene, butene, and pentene, and they all follow the general formula CₙH₂ₙ.
What makes alkenes special is their ability to undergo addition reactions. The double bond can "open up" to allow other atoms to attach, turning the unsaturated alkene into a saturated compound. This is something alkanes simply can't do because they only have single bonds.
When alkenes burn, they produce smoky flames due to incomplete combustion. This happens because the double bonds make it harder for complete combustion to occur, which is why alkenes aren't typically used as fuels despite being hydrocarbons.
Key Point: The C=C double bond is what gives alkenes their reactive nature - it's like a "hook" that other molecules can attach to!
