Elimination (AQA AS Chemistry): Revision Note

Mechanism: Elimination

• In an elimination reaction, a small molecule is removed leaving behind an alkene

• This is another reaction of halogenoalkanes

• The halogenoalkanes are heated with ethanolic sodium hydroxide causing the C-X bond to break heterolytically, forming a X^– ion and leaving an alkene as organic product

  • E.g. bromoethane reacts with ethanolic sodium hydroxide when heated to form ethene

Hydrogen bromide is eliminated to form ethene

Elimination Mechanism of 2-bromopropane with hydroxide ions