This memory aid covers Memory Aid: AlkENE = doublE bond = Extremely reactive within Alkenes for GCSE Chemistry. Revise Alkenes in Organic Chemistry for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 11 of 14 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
🧠 Memory Aid: AlkENE = doublE bond = Extremely reactive
The letters in alkENE remind you:
- ENE — contains a C=C doublE bond (the E in ENE)
- E — Extremely reactive compared to alkanes
- General formula: CₙH₂ₙ — just 2n hydrogens (count: 2 × carbons)
For the bromine water test: "AlkENE turns it clear, alkaNE leaves it there" — alkenes decolourise bromine water; alkanes do not.
For addition reactions: DOUBLE bond → becomes SINGLE bond when atoms ADD across it. Double → Single = Addition.
Practice questions for Alkenes
What is the general formula for alkenes?
Explain what is meant by the term 'unsaturated' when applied to alkenes.