4.2.2: Haloalkanes Flashcards
Give the reagent and conditions to go from a haloalkane to an alcohol (hydrolysis)
aq Warm NaOH and reflux
What diagram would be drawn for the hydrolysis of a haloalkane to an alcohol ? Give specific features
Reflux
- Pear shape flask
- Condenser
- Heat source
- Water in at bottom and out at top
Show an equation for the formation of a chlorine radical from chlorotrifluoromethane
CF3Cl → CF3* + Cl*
Give 2 features of a good aerosol
Low boiling point and non-toxic
What is the greenhouse effect of CO2 in the atmosphere dependent on ?
- Residence time
- Atmospheric concentration
Give a biodegradable alternative to CFCs
Hydrocarbons
Give 2 reasons why CFCs are still a concern to ozone depletion
- Long residence time
- CFCs are still being used aswell as other ozone depleting substances
Why don’t CFCs often hydrolyse in water ?
Because the C-F and C-Cl bonds require a lot of energy to break
Why is ozone depletion a health concern ?
More UV reaches Earth’s surface causing increased risk of skin cancer and cataracts
How does the presence of CFCs lead to ozone depletion ?
Catalyses the decomposition of ozone
How does temperature affect the rate of hydrolysis of haloalkanes?
A higher temperature means a quicker time for precipitates to form as particles have more energy for more collisions
Define nucleophile
An electron pair donor
What mechanisms do haloalkanes follow ?
Nucleophilic substitution
What are the products of the hydrolysis of a haloalkane by aqueas alkali?
Alcohol + halide ion
What is the reactivity of haloalkanes and the rate of hydrolysis ?
Reactivity and rate of hydrolysis increases down group as C-halogen bond enthalpy decreases so C-I is hydrolysed the fastest (yellow precipitate forms first)
