Halogenoalkanes Flashcards
What is nucleophilic substitution?
When a halogen in a halogenoalkane is replaced by a nucleophile
What is a nucleophile?
An electron pair donor
Why does nucleophilic substitution happen in halogenoalkanes?
Because of the polar bond between the carbon and halogen atoms
What nucleophiles do halogenoalkanes undergo substitution with?
OH-
CN-
NH3
halogenoalkane + OH- (aq) –> ?
alcohol
halogenoalkane + CN- –> ?
nitrile
halogenoalkane + NH3 –> ?
amine
What happens during nucleophilic substitution?
The nucleophile attacks a delta+ carbon atoms and the bond with the halogen breaks
What affects the nucleophilic substitution rate of reaction? Why?
Bond enthalpy
> higher bond enthalpy =>stronger bond => harder to break => slower reaction
What is the reagent in elimination?
OH- in alcoholic conditions/in ethanol
What does the reagent in elimination act as?
A base (takes proton)
A nucleophile
Whys is ozone beneficial?
It absorbs UV radiation
How are chlorine atoms formed in the upper atmosphere?
When UV causes C-CL bond in chlorofluoroalkanes to break
Why is having free radical chlorine atoms in the atmosphere bad?
They catalyse the decomposition of ozone and contribute to the hole in the ozone layer
