haloalkanes

Question 1

what are nucleophiles?

Answer 1

species that donate a lone pair of electrons

Question 2

give 3 examples of nucleophiles

Answer 2

• water
• ammonia
• hydroxide ions

Question 3

what reaction mechanism do haloalkanes undergo?

Answer 3

nucleophilic substitution

Question 4

what type of reaction is nucleophilic substitution?

Answer 4

hydrolysis
- bond is broken through addition of water

Question 5

describe the nucleophilic substitution mechanism

Answer 5

• curly arrow from nucleophile lone pair to delta positive carbon on haloalkane
• arrow from delta pos carbon to delta negative halogen
• alcohol and halide ion forms as lone pair from nucleophile is attracted and donated to carbon

Question 6

state the reagents and the conditions for nucleophilic substitution of haloalkanes

Answer 6

• heat under reflux
• aqueous sodium hydroxide

Question 7

what determines how fast a carbon halogen bond will break?

Answer 7

bond enthalpy

Question 8

which haloalkane will react fastest and why?

Answer 8

iodoalkanes
- C-I bonds are weakest so easiest to break
- fastest rate of hydrolysis

Question 9

how does primary, secondary or tertiary halogenoalkane status affect rate of hydrolysis?

Answer 9

• tertiary reacts fastest
• intermediate carbocation formed is most stable

Question 10

how do CFCs deplete the ozone layer?

Answer 10

• UV radiation provides enough energy to break the carbon halogen bond
• by homolytic fission forming radicals

Question 11

what other radicals are responsible for ozone depletion?

Answer 11

nitrogen oxide radicals