Halogenoalkanes

• Alkanes react with halogens in photochemical reactions to form halogenoalkanes
• a free radical is a particle with an unpaired electron
• free radicals form when a covalent bond splits equally, giving one electron to each species
• The steps of free radical substitution

  1. initiation
  2. propagation
  3. substitution
  4. termination
• chlorofluorocarbons (CFCs) are halogenoalkane molecules where all of the hydrogen atoms have been replaces by chlorine and fluorine molecules
• Halogenoalkanes can react with hydroxyls in nucleophilic substitution reactions to produce alcohols
• Halogenoalkanes can react with cyanides (C≡N) to produce nitriles
• halogenoalkanes can react with ammonia to form amines
• ozone absorbs ultraviolet radiation
• Chlorine atoms catalyse the decomposition of ozone cause the ozone layer to become damaged