Comparing Reactivity Of Alkanes and Alkenes
Aim: To compare the reactivity of an alkane and an alkene
Hypothesis: The cyclohexene would react to the bromine water and turn colourless, whilst the cyclohexane won’t react.
Risk Assessment: What’s the problem? | How do you fix? | How does it work? | Bromine water is corrosive to the skin | Wear gloves | Stops the Bromine water from reaching skin | Cyclohexane/ene is highly flammable | Keep away from naked flames. | No naked flame = no ignition. | Bromine water is very toxic if inhaled | Conduct experiment in fume cupboard | Gets rid of the fumes so it doesn’t get inhaled. |
Equipment: * Dropper bottle of Cyclohexane | * Dropper bottle of Cyclohexene | * Bromine Water | * 4 Test Tubes | * Test tube rack | * Safety Glasses | * Gloves | * 1 pipette | * Fume cupboard | * 2 Dropper bottles labelled A and B, one containing a hexane and one containing a hexene | * Cork Stopper x4 | Method: NOTE: * Conduct experiment under dull lighting, as the cyclohexene can react with light. * Conduct the experiment inside the fume cupboard, due to the fumes the chemicals give off. 1. Gather all equipment listed, wear safety glasses and gloves, 2. Add 10 drops of Bromine water to a test tube 3. Add 10 drops of cyclohexane to the same test tube 4. Close the test tube with a cork stop, shake gently then place it on the test tube rack 5. Repeat steps 2-4 for cyclohexane then to test tubes “A” and “B” to identify alkene 6. Compare test tubes 3 and 4 with 1 and 2 by checking which test tubes decolourised to determine which one is a hexane and a hexene out of “A” and “B”
Results: Substance | Reaction with Bromine Water | Hydrocarbon
(Saturated/unsaturated) | Cyclohexane | Remained yellow | Saturated | Cyclohexene | Yellow Colourless | Unsaturated | A | Yellow Colourless |