Lesson 3 of 6 · Organic Chem
Experiment⭐ 30 XPAlkenes and the Bromine Water Test
Organic Chem.
🎯 Your mission
Predict it first. Then prove yourself right (or wrong).
⚡ The twist
Nature loves to surprise the careful watcher.
Mind = Blown
🔬 The more you look, the more nature shows you.
Make a hypothesis first
Before you start: write down what you think will happen, and why.
What You'll Learn
Alkenes contain a carbon-carbon double bond and have formula CₙH₂ₙ. That double bond makes them far more reactive than alkanes. Bromine water is decolourised from orange to colourless by an alkene, but is unchanged by an alkane.
Key Words
Tap a word to see its definition.
Materials Needed
- bromine water
- hexane
- cyclohexene
- test tubes with bungs
- gloves
Safety First
- Bromine water is toxic and corrosive — fume cupboard, goggles and gloves, and never inhale the vapour.
- Hydrocarbons are highly flammable: no flames anywhere in the room.
Steps
Read the explanation above and note the two key terms before you start.
Add bromine water to samples of an alkane and an alkene and shake gently. Record the colour of each after mixing and use the result to identify an unknown third sample.
Record what actually happened, including anything that did not match what you expected.
Write a conclusion that answers the question this lesson opened with, and state your uncertainty.
Check Your Understanding
Question 1
1 of 2Bromine water turns from orange to colourless with an:
Where you see this in real life
This shows up in your everyday life more than you'd think.
Stretch Challenge
Try this in real life this week.
Try one experiment in real life this week — even a tiny one.
For the dinner table
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Alkenes and the Bromine Water Test
Predict it first. Then prove yourself right (or wrong).
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