4.2.2 Haloalkanes Flashcards
3 examples of nucleophiles?
Cyanide, ammonia, hydroxide
ionic equation for bromomethane + sodium hydroxide: ionic
Ch3br + oh- = ch3oh + br-
What is the name of the mechanism for haloalkanes, reagents and conditions?
Nucleophilic substitution
hot aqueous sodium or potassium hydroxide
heat under reflux
what is hydrolosis?
The breaking down of a molecule using water / aqueous alkali
Reagents and conditions for hydrolosis of the haloalkanes?
Reagent: Aqueous silver nitrate (AgNO₃) in ethanol
Conditions: Heat gently
Briefly outline how you would compare the reaction rates
1) add the silver nitrate to the ethanol
2) warm/ heat in water bathe
3)add same amount of each halogen
4)the precipitate formed goes cloudy
5) monitor rate of precipitate formed
we warmed the halo alkane with aq silver nitrate with ethanol added so what is the purpose of water in this method?
To produce the OH- ion which will act as a nucleophile
why do we use ethanol in this method?
To allow the agno3 to mix.
What determines the rate of hydrolysis of the haloalkanes and which bond is strongest?
Bond enthalpy
C-Cl (if C-F is not there)
What is the ozone layer?
a layer with high concentration of o3
How is the concentration of the ozone in the atmosphere maintained?
o3 (double arrow) o2 + o3
rate of formation of ozone = rate of depletion
What is the global concern of ozone depletion
more uv being let through
greater risk of sunburn
how does ozone depletion occur
radicals are formed from cfcs which are reactive and react with ozone
What are cfgs
chlorofluro carbons
with low reactivity and its high volatile - non toxic
examples of cfgs
fire extinguishers
propellant/solvents
why do cfgs have to be stable
so it doesn’t react with ozone and deplete it
