Organic ChemistryRequired Practical
Testing for Alkenes: The Bromine Water Test
Part of Alkenes — GCSE Chemistry
This required practical covers Testing for Alkenes: The Bromine Water Test 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 5 of 14 in this topic. Revise both the method and the reason for each step, because practical questions often test understanding rather than pure recall.
Topic position
Section 5 of 14
Practice
20 questions
Recall
15 flashcards
🧪 Testing for Alkenes: The Bromine Water Test
This is THE classic test for unsaturation — you MUST know this!
What you do:
Add a few drops of bromine water (orange/brown solution) to your sample
Add a few drops of bromine water (orange/brown solution) to your sample
With alkenes:
Bromine water turns colourless (decolourised)
Addition reaction: C=C + Br₂ → C-CBr-CBr (dibromoalkane)
Bromine water turns colourless (decolourised)
Addition reaction: C=C + Br₂ → C-CBr-CBr (dibromoalkane)
With alkanes:
Bromine water stays orange (no reaction)
Alkanes don't have C=C bonds to react with
Bromine water stays orange (no reaction)
Alkanes don't have C=C bonds to react with
Safety: Bromine water is toxic and can cause burns. Always use in a fume cupboard and wear eye protection.