Comparing Alkanes and Alkenes
Comparing alkanes and alkenes
Aim:
Is cyclohexane more or less reactive than cyclohexene in the presence or absence of light
Hypothesis
The cyclohexene will reactive the fastest because being an "ene" it has a electron rich area making it more reactive than cyclohexane but neither one of the will react without light
Materials * 4x 250ml conical flasks * 2 rubber stoppers * Aluminium foil * Cyclohexane * Cyclohexene * Bromide water * Measuring cylinder
Risk assessment risk | level | Precautions taken | Organic compound in eyeor on skin | medium | Glasses, lab coatgloves | Inhaling organic compound | high | Fume cabinet | Bromide water in eye or onskin | medium | Glasses, lab coatgloves | Laceration from broken glass | low | Minimalizing movement of glassware |
Method 1. Wrap two of the flasks in aluminium foil and make a lid, make sure it is light proof 1. Put 5ml cyclohexane in one of both the covered and un-covered flasks and put the rubber stopper in the un-covered flask an the aluminium foil lid on the covered flask 1. Put 5ml of cyclohexene in the two remaining flasks and put the stopper and lid on as in step 2 1. Add 5 drops of bromide water in to the uncovered flasks making note of which flask contains the cyclohexane and the cyclohexene. 1. Observe the reaction times of the bromide water in the organic compound (the bromide water's colour should disappear) 1. Repeat step 5 with the covered 1. Leave the covered flask for a couple of minutes 1. Carefully unwrap the flasks one at a time making note what the flask it is and observe the reactants inside 1. Repeat the last step with other flask 1. Record results Variables Controlled: amount of bromide water and amount of organic compound
Independent: alkane or alkene, exposure to light
Dependent: rate of decolourisation of the bromide water Results | cyclohexane |
Aim:
Is cyclohexane more or less reactive than cyclohexene in the presence or absence of light
Hypothesis
The cyclohexene will reactive the fastest because being an "ene" it has a electron rich area making it more reactive than cyclohexane but neither one of the will react without light
Materials * 4x 250ml conical flasks * 2 rubber stoppers * Aluminium foil * Cyclohexane * Cyclohexene * Bromide water * Measuring cylinder
Risk assessment risk | level | Precautions taken | Organic compound in eyeor on skin | medium | Glasses, lab coatgloves | Inhaling organic compound | high | Fume cabinet | Bromide water in eye or onskin | medium | Glasses, lab coatgloves | Laceration from broken glass | low | Minimalizing movement of glassware |
Method 1. Wrap two of the flasks in aluminium foil and make a lid, make sure it is light proof 1. Put 5ml cyclohexane in one of both the covered and un-covered flasks and put the rubber stopper in the un-covered flask an the aluminium foil lid on the covered flask 1. Put 5ml of cyclohexene in the two remaining flasks and put the stopper and lid on as in step 2 1. Add 5 drops of bromide water in to the uncovered flasks making note of which flask contains the cyclohexane and the cyclohexene. 1. Observe the reaction times of the bromide water in the organic compound (the bromide water's colour should disappear) 1. Repeat step 5 with the covered 1. Leave the covered flask for a couple of minutes 1. Carefully unwrap the flasks one at a time making note what the flask it is and observe the reactants inside 1. Repeat the last step with other flask 1. Record results Variables Controlled: amount of bromide water and amount of organic compound
Independent: alkane or alkene, exposure to light
Dependent: rate of decolourisation of the bromide water Results | cyclohexane |