4.2.2 haloalkanes Flashcards
how do you get from a haloalkane to an alcohol and draw the mechanism
NaOH-aqueous (Aq)
in booklet
how do you get from a haloalkane to a nitrile
and draw the mechanism
CN-/ethanol
in booklet
how do you get from a haloalkane to a amine
and draw the mechanism
NH3/ethanol
in booklet
what is a nucleophile
an electron pair donor
attracted to low electron density
eg-NH3
OH-
how do you calculate the rate of hydrolysis for haloalkanes
-the haloalkane is heated with aqueous silver nitrate in the presence of an ethanol solvent
-a water bath between 40-80 degrees is used to heat the mixtures (so they can equilibrate)
-the halide ion is released from the haloalkane and reacts with silver nitrate forming a precipitate
-measure time taken for each precipitate to form
how does the rate of hydrolysis change as you go down the carbon-halogen bonds
rate of hydrolysis increases as bond enthalpy decreases
-in make schemes make reference to the C-I bond
what are the colour of precipitates and how long do they take to form
AgCl
AgBr
AgI
AgCl-white-slow
AgBr-cream-fast
AgI-yellow-fastest
what are CFCs responsible for the depletion of
ozone layer
what is the role of the ozone
ozone absorbs UV-B radiation from the sun
-this UV causes cancer
what are the 2 steps showing how the ozone is formed
o=o (arrow)-> o radical + o radical
o2 + o radical (reversible sign)-> o3
write the equation for the breakdown of CF2Cl2 and propagation steps
CF2Cl2->(radical)CF2Cl + (radical) cl
(radical) Cl + 03 -> (radical) clo ++ o2
(radical)clo + o -> (radical) cl + o2
OVERALL-o3 + 0 -> 2o2
what do the chlorine radicals act as
catalysts
write the equation for the breakdown of NO and propagation steps
(radical) NO + O3 -> (Radical) NO2 + O2
(radical) NO2 + O -> (radical) NO + o2
OVERALL- o3 + o -> 2o2
what type of bonf fission does CF2Cl2 break down as and what substance breaks this down
UV light
Homolytic fission
