starryXnite said:
I'm writing a prac report on comparing the reactivities of alkanes and alkenes but I was away for the prac so I'm kinda stuck on writing the experiment
can anyone help with with some information about what I need to write?
Like implication and application?
thanks in advance...
Aim: to compare the reactivities of alkanes and alkenes.
Hyopthesis: alkenes are more reactive due to an electron dense double bond.
Materials/method:
1) Use cyclohexane and cyclohexene.
2) Equal 1mL quantities of each hydrocarbon in seperate test tubes.
3) Cover test tubes in aluminium.
4) Add 3-4 drops of bromine water to each test tube.
5) Stopper and shake test tubes.
6) Remove foil, examine liquids.
7) Pour contents of tubes into organic waste bottles.
Justification of prodecure:
> Straight chained compounds are highly toxic, hence cyclic compounds are used.
> Liquids are used to more easily view changes.
> Alkanes can react in U.V light with halogens, hence aluminium foil is used around test tubes.
Risks:
> Bromine: harmful and highly corrosive --> carry out in fume cupboard, wash hands after use.
> Hydrocarbons: highly flammable --> keep away from naked flames, toxic by skin absorption and inhalation --> carry out in fume cupboard and wash hands after use.
Controls:
> Same quantities of hydrocarbons.
> Same amount of bromine water for each test tube.
> Same waiting time for each test tube.
Results/observations:
> The cyclohexene decolourised the bromine water i.e. reacted with the bromine.
Conclusion:
> The experimental results suggest that alkenes are more reactive then alkenes.
> This supports the hypothesis.
Issues of accuracy/reliability/validity:
> Accurate? Yes. Experimental data mirrors theoretical data.
> Reliable? Yes. All groups got the same results.
> Valid? Yes. Accurate, reliable, controlled.
Improvements to method/appartus:
> Use a range of different alkanes and alkenes to show the reactivity test applies to all alkanes and alkenes.
