2.6 - Halogenoalkanes

• What is the typical reaction that chloroalkanes (halogenoalkanes)undergo?

  Nucleophillic substitution
• Give some useful properties of the halogenoalkanes:

  • great solvents
• What test can be carried out to identify a halogenoalkane?

  • Silver nitrate test
• A halogenoalkane can be converted into an alkene, what conditions are needed?

  Sodium hydroxide dissolved in ethanol
• What kind of reaction occurs where a halogenoalkane is converted to an alkene?


  Elimination
• What are the products of a nucleophilic substitution of a halogenoalkane?

  Alcohol and a halide ion.
• What conditions are needed for a halogenoalkane to be converted to an alcohol and a halide?

  A water solvent (e.g. sodium hydroxide dissolved in water)
• What nucleophile is present when sodium hydroxide is used in nucleophillic subtitution?

  -OH ion
• How are CFC's damaging the ozone layer?

  CFC molecules form chlorine free radicals when they come into contact with UV light, which can then react with an ozone molecule.
• Why are HFC's (fluorine containing) replacing CFC's?

  They contain no chlorine and do not split into free radicals that will attack the ozone under UV light due to the carbon-fluorine bond being so strong.
• What are the products of the elimination reaction of halogenoalkanes?

  Alkenes + water + nucleophile (halide)