Alcohols

• Describe how ethanol is produced from sugar solution. Give the name of this process.

  • fermentation
  • add yeast
  • anaerobic conditions
  • warm
• Alcohols

  • contain the functional group -OH
  • covalent bond between oxygen and carbon atom
• General formula of an alcohol

  • C(n)H(2n+1)OH
• First four alcohols

  • methanol
  • ethanol
  • propanol
  • butanol
• How to identify alcohol from formula and name?

  • must contain -OH functional group
  • must contain 'ol'
• Alcohols reactions with sodium

  • produce hydrogen
• Properties of alcohols 


  • flammable
  • dissolve completely in water to form neutral solutions
  • can be oxidised by an oxidising agent
• Example of oxidising agent

  • oxygen
  • in air
• Combustion of alcohols

  • Burn in air (oxygen)
  • produce carbon dioxide + water
• Conditions of fermentation

  • anaerobic conditions
  • mixed with yeast
  • slightly acidic
• Uses of alcohols

  • alcoholic drinks
  • fuels
  • solvents
• Why are alcohols suitable solvents?

  • hydrocarbons, oils and fat are insoluble in water
  • but will dissolve in alcohols
  • good for industry
• Why is methylated spirit coloured purple?

  • deter people from drinking it
  • its poisonous
• Fermentation word equation

  glucose --> carbon dioxide + ethanol
• Describe and explain what happens to the limewater during the experiment

  • goes cloudy
  • carbon dioxide produced
  • because (a precipitate of or solid) calcium carbonate
  • efferservence
• Why is yeast needed in fermentation?

  • Contains enzymes that break down sugar to glucose.
  • The yeast respire anaerobically using the glucose to form ethanol and carbon dioxide.
• Alcohols + water

  • dissolves completely in water to form a neutral solution
  • solubility decreases as the length of the alcohol gets longer
• Is ethanol as soluble as methanol?

  • No
  • Solubility decreases as the length of the alcohol increases