Haloalkanes Flashcards
what is a secondary haloalkane?
draw an example
Two carbons attached to the
carbon atom adjoining the
halogen
what is a primary haloalkane?
One carbon attached to the
carbon atom adjoining the
halogen
what is a tertiary haloalkane?
draw an example
Three carbons attached to the carbon atom adjoining the halogen
what is a nucleophile?
electron pair donor
give 3 examples of nucleophiles
:OH-, CN:-, :NH3
what mechanism do haloalkanes undergo?
nucleophillic substitution
The rate of these substitution reactions depends on the strength
of the ____ bond
The ____ the bond, the ____ it is to break and the faster the reaction.
C-X , weaker, easier
draw the template for a nucleophillic substitution recation
The ____ are the fastest to substitute and the
_____ are the slowest. The strength of the C-F bond is
such that fluoroalkanes are very ____
iodoalkanes, fluroalkanes
draw tetrachloromethane
draw 1,1-dichloroethene
draw 1,2-dibromo-2-methylbutane
draw 1,2-dibromocyclohexane
name CH3CH2CH2I
1-iodopropane
name
2,3-dibromobutane
name
1-fluoro-2-methylpent-2-ene
write an equation for nucleophilic substitution with aqueous hydroxide ions of 1-bromopropane
In aqueous solution; Heat under reflux
draw the mechanism for nucleophilic substitution with aqueous hydroxide ions of 1-bromoethane
define hydrolysis
Hydrolysis is defined as the splitting of a molecule ( in this case a haloalkane) by a reaction with water
Water is a ____ nucleophile but it can react slowly with haloalkanes in a substitution reaction. Use ____ OR heat
for more than ____ minutes
poor, reflux , 20
in hydrolysis reactions, The ____ the precipitate is formed, the ____ the substitution reaction and the ____ reactive the haloalkane
quicker, faster , more
what colour precipitates do the silver halides form?
Aqueous ____ is added to a haloalkane and the
halide leaving group combines with a ____ ion to form a
____ precipitate.
silver nitrate, silver , silver halide
CFC’s were developed for use as aerosols, refrigerants, and in air-conditioning due their low
____, ____ and non-____
reactivity, volatility, toxicity
write the equation for ozone being broken down and reformed
how is ozone formed?
UV light causes an O2 molecule to split into free radicals
O2 + UV-light –> O + O
When the free radical hits another O2 molecule ozone forms
O + O2 –> O3
what other radicals are responsible for ozone depletion?
nitrogen oxide radicals
name 2 alternatives to CFCs
HCFCs + HFCs
hydrocarbons
The chlorine free radical atoms ____ the decomposition of ozone due to these reactions because they are regenerated.
give the equations
catalyse
why do CFCs still concern us?
CFCs are still entering the atmosphere from disused items and are still used for some purposes and by some countries.
CFCs have a long lifetime in the atmosphere and it takes a long time for CFCs to reach upper atmosphere.
