halogenoalkanes Flashcards
what are halogenoalkanes
they contain polar bonds, they are saturated organic compounds that contain 1 hydrogen atom
what do halogenoalkanes undergo substitution reactions with
OH-, CN-, NH3
why is the bond between the carbon and halogen a permanent dipole
it has a large difference in electronegativity between the c-h , with electrons closer to the halogen atoms, the partial negative charge on the carbon atoms will make it easy to attack the electron rich nucleophiles, it will undergo nucleophilic substitution to attack the hydroxide ions
trend in electronegativity down the group
it will decrease so the polarity of the bond will also decrease, so the iodoalkanes are more reactive because the bond enthalpy will decrease down the group
what happens when haloalkanes react with OH-
there are two possibilities they can either be substituted or eliminated
what are conditions of a substitution reaction
aqueous ethanol as a solvent, aqueous hydroxide and mixture must be warmed
what are conditions of a elimination reaction
ethanol as a solvent, anhydrous conditions and high temperature and heat under reflux
what is ozone
it is formed naturally in the upper atmosphere, is beneficial because it absorbs ultraviolet radiation
how are chlorine atoms formed
they are formed in the upper atmosphere when uv radiation causes the c-cl bond in the chlorofluorocarbons to break
what are chlorofluorocarbons
a type of organic compound that contain chlorine and fluorine atoms, they diffuser through layers of the atmosphere where they are exposed to UV radiation
what are the role of chlorine atoms
they catalyse the decomposition of ozone and contribute to the hole in the ozone layer
what is the role of chlorine radicals
they are regenerated and act as a catalyst in the breakdown of ozone into oxygen,
what causes cancer and burns
holes within the ozone layer are the likelihood of skin caner and sunburns
