haloalaknes Flashcards
what bonds do haloakanes conatin
polar
what is a nucleophile and examples
‘postive liking’ the contain a lone electron pair that is attacted to &+ region of molecules
CN:-
:NH3
-:OH
haloalkane –> alchol
nucleophyliic subsistion
NaOH
aq, heat, under reflux
nucleophile attack the &+ carbon and the electron are transferred to the chlorine
haloakane –> amine
nucelphyliic subsistion
excess NH3
ethanol, heat, pressure
nucleohlilke attacks the &+ carbon and electron transffered to chlorine, the intermiate formed has a N+ atom so electrons tranferred to it causing a hyrdogen to be lost to
haloalkane –> nitrile
nucelophyllic subsistution
KCN
ethanol and water
nucleophile attack the &+ carbon and electrons transferred to chlorine
explain why the carbon halogen bond enthalpy influences the rate of reaction
the harder it is to break the slower the reaction will be
haloalkane –> alkene
elimination
KOH
ethanol, reflux
nucleophile acts as a base and accepts a proton removing a hydrogen atom from the molecule this results in elimination of halide too producing a carbon-carbon double bond
can only occur from secondary and tertiary haloalkanes
ozone is beneficial because
it is formed naturally in upper atmosphere and absorbs ultraviolet radiation
why are CFcs banned do not need to use equations
research by different groups in the scientific community provided evidence for legislation to ban use of CFCs in solvents and refigerants as when UV radiation absorbed by CFCs in upper atmosphere breaking the carbon-halogen bond to form chlorine atoms in the upper atmosphere which catalyze the decomposition of the ozone and contribute to the hole in the ozone layer
use equations to explain how chlorine atoms catalyze decomposition of ozone
O3 + Cl* –> *OCl + O2
OCl + O3 –> 2O2 + Cl
overall : 2O3 –> 3O2
soloution to CFCs decomposting the ozone
Chemists have now developed alternative chlorine free compounds to minimize ozone depletion and global warming
