Reaction of alkane, alkene & alkyne
Title: Reaction of Saturated and Unsaturated Hydrocarbons
Objective: To carry out chemical test to differentiate an alkane and an alkene.
Apparatus: dropper, test tube, hot plate
Chemical reagents: bromine, toluene, cyclohexane, cyclohexene, acidified KMnO4, dichloromethane
Method
A. Bromine test
1.6 clean and dry test tube were taken and were labelled them A until F
2.1ml of dichloromethane were placed into each test tube
3.1 ml of cyclohexane were placed into tubes A and B,1 ml cyclohexene were placed into test tube C and D,1ml toluene to test tube E and F
4. 5 drops of bromine water were placed into each test tube
5. Test tube A, C and E were placed in the dark; test tube B,D, and F under the sunlight. All the tubes were leaved for 10 minutes
B. Oxidation Test with Acidic KMnO4
1. 3 clean and dry test tubes were labelled
2. 1ml cyclohexane, cyclohexene and toluene were placed into each test tube respectively
3. Few drops of acidic KMnO4 were placed into each test tube 4. The test tube were heated in a water bath
5. Observation were recorded
5. Observation
Reaction with bromine water Test | Observation | Inference | 1ml of cyclohexane + bromine water + sunlight | Orange colour changes to colourless when exposed to light | Alkane present | 1ml of cyclohexane + bromine water + dark | No colour change | Alkane present | 1ml of cyclohexene + 3 drops of bromine water + shaking | Decolourisation of bromine water. No colour change | Alkene present |
Reaction with aqueous potassium permanganate Test | Observation | Inference | 2ml of cyclohexane + 2 dropsKMnO4 + shaking | No colour change with the addition of aqueous KMnO4 | Presence of Alkane | 2ml of cyclohexene + 2 dropsKMnO4 + shaking | Colour changes to colourless with brown precipitate | Presence of Alkene |
Reaction with potassium permanganate and aromatic compound Test | Observation | Inference | 1ml of