Organic Synthesis

• Describe how a Quickfit apparatus is connected

  Grease the joints using some petroleum jelly on the inside of the joints before connecting the pieces together
• Continuous water flow around the condenser in a distillation setup


  So that the water remains cool in order for the mixture to be distilled
• Describe a method that can be used to separate immiscible liquids

  1. Pour the mixture into a separating funnel and some distilled water

  2. Add the stopper and invert the flask to mix the mixture

  3. Equalise the pressure by opening the stopper as required

  4. Continue shaking until there is no 'whistle' sound

  5. To collect the water in the lower layer, open the stopper and place a beaker under the spout

  6. Use another beaker to collect the desired organic layer

  7. Shake the liquid with some drying agent
• Drying agents


  • Magnesium sulphate
  • Calcium chloride
• How to use drying agents


  1. Add a selected drying agent to the organic product

  2. If the drying agent forms clumps add some more until they are moving freely

  3. Use gravity filtration to collect the dry product

  4. Filtrate is the product
• Re-distillation


  When a liquid is purified by using multiple distillations
• How can unsaturated hydrocarbon be tested? What are the observations?

  1. Use bromine water

  2. Add few drops of bromine water to the sample and mix well

  3. Positive test - bromine water turns colourless
• What are the reagents used to test haloalkanes and what are the observations?

  1. Reagents - silver nitrate, ethanol and water

  2. Observations - chloro-: white precipitate, bromo-: cream precipitate, iodo-: yellow precipitate
• Reagents that can be used to test carbonyls

  • Acidified potassium dichromate
  • Fehling's solution
  • Tollens' reagent
• Observations when acidified potassium dichromate reacts with ketones and aldehydes


  Ketones - no change, Aldehyde - turns from orange to green colour
• Observations when Fehling's solution is reacted with ketones and aldehydes


  Ketones - no change, Aldehyde - dark red precipitate
• Observations when Tollens' reagent is reacted with ketones and aldehydes


  Ketones - no silver mirror, Aldehydes - silver mirror
• Reagents that can be used to test carboxylic acid

  • Universal indicator - pH of weak acid
  • Reactive metal - hydrogen effervescence
  • Metal carbonate - carbon dioxide effervescence