Alcohols

• the general formula of an alcohol is CnH2n+1OH
• alcohols can be oxidised to form carboxylic acids
• fermentation is the process of using yeast to convert a type of of carbohydrate called sugars into alcohol
• How to make a solution of ethanol by fermentation

  1. mix yeast and a solution of carbohydrates in a clean container and a warm place
  2. keep the mixture between 30 and 40 degrees
  3. keep the mixture in anaerobic conditions
  4. when the concentration of alcohol reaches 20%, the fermentation reaction stops because the yeast gets killed off by the alcohol
• fractional distillation is used to concentrate ethanol

  1. a dilute solution of ethanol is produced by fermentation
  2. fractional distillation separates mixtures by heating them
  3. ethanol has a lower boiling point than water so ethanol evaporates and rises up the fractioning column
  4. a condenser is used to condense the ethanol vapour by cooling it
• Alcohols can be used for fuel because when they're burned, they release energy
• Alcohols are soluble in water and form neutral solution

  as the number of carbon atoms increases, the solubility decreases
• When alcohols react with oxidizing agents, they produce a carboxylic acid and water