Alcohols

• Why do alcohol dissolve in water ?

  Because hydrogen bonds form between the polar O-H functional group and the polar water molecules.
• Write the equation for the complete combustion for ethanol.

  C2H5OH (l) + 3O2 (g) --> 2CO2 + 3H2O (l)
• What are the reagents for the oxidation of alcohols ?

  K2Cr2O7 / H+
• What colour does the acidified dichromate change to during oxidation ?

  orange to green
• What does the distillation of a primary alcohol produce ?

  aldehyde
• Why is it essential for water to enter the bottom of the condenser ?

  + So the jacket is filled completely = efficient cooling

  + Hot vapours reach the coolest section of the condenser last
• What is reflux ?

  The continuous boiling and condensing without loss of volatile materials.
• Is water produced when an aldehyde is oxidised ?

  No
• What is the name of the reaction when an alcohol turns into an alkene ?

  Dehydration or Elimination
• What is the catalyst and conditions required to turn an alcohol into an alkene ?

  catalyst : concentrated H2SO4

  conditions : heat
• What is the reaction called when an alcohol is made into a haloalkane ?

  substitution
• How is a haloalkane prepared ?

  Alcohol is heated under reflux with NaX and H2SO4
• What is reacted with alcohol to form a haloalkane ?

  H2SO4 and NaX
• What is the overall equation for the formation of bromoethane using alcohol ?

  H2SO4 + NaBr + CH3CH2OH --> NaHSO4 + CH3CH2Br + H2O