Haloalkanes Flashcards
Suggest two reasons why there is still concern about ozone depletion. (2)
- CFCs take many years to reach ozone layer;
- CFCs are still being used;
- there are other ozone depleting substances (NO, HFCs);
Suggest a property that made CF3Cl suitable as a propellant in an aerosol.
volatile, low BP, unreactive, non-flammable
homolytic fission
covalent bond breaks
each bonded atom retains 1 electron/ shared equally
Suggest which bond is most likely to be broken when CF3Cl is exposed to
ultraviolet radiation. Explain your answer.
C-Cl
weakest bond
Identify the two free radicals most likely to be formed when CF3Cl is exposed to
ultraviolet radiation.
Cl•
CF3•
Uses of CFCs
- (propellant in) aerosols because it is volatile/ unreactive/ non-toxic/ easily compressed
- blowing polystyrene because it is unreactive
- dry cleaning because it is a good solvent for organic material
- degreasing agent because it is a good solvent for organic material
- fire extinguishers because it is non-flammable
rate of hydrolysis reaction - why was hot water bath used?
providing kinetic energy so more successful collisions to speed up ror
rate of hydrolysis reaction - explain the 2 roles of HNO3 in the reaction
- provides nucleophile
- provides indicator
rate of hydrolysis reaction - explain purpose of ethanol in reaction
cosolvent as haloalkanes insoluble in water
rate of hydrolysis reaction - what reagents do you need?
-heat AgNO3
- ethanol
- 1-bromo,1-chloroand 1-iodobutane (3 drops added to ethanol)
iodo forms precip -> bromo -> chloro
rate of hydrolysis reaction - what is the equation of the hydrolysis of a haloethane?
CH3CH2X + H2O -> CH3CH2OH + HX
rate of hydrolysis reaction - equation for halogen reacting with silver ion
Ag+ (aq) + X-(aq) -> AgX (s)
rate of hydrolysis reaction - why does iodine react that fastest?
C-I bond is the weakest
How is ozone formed? (eq)
O2 —->(UV) 2O•
O2 + O• —> O3
How is ozone broken down? (eq)
O3 —–> (UV) O2 + O•
