Composition of inks

• What is the aim of simple distillation in this experiment?

  To investigate the composition of inks
• What equipment is needed for simple distillation?

  • 250 cm​3​ beaker
  • Quickfit Apparatus
  • Round-bottomed or pear-shaped flask
  • Bunsen burner
  • Clamp and stand
  • Cold water tap
  • Thermometer
• Why should the flask not be heated too strongly during distillation?

  To prevent water from boiling over into the beaker
• What should the position of the condenser be during distillation?

  The condenser should be horizontal
• What is the purpose of the thermometer in the distillation setup?

  To identify the solvent by its boiling point
• What are the safety precautions to follow during distillation?

  • Turn off gas or use orange safety flame
  • Tie back long hair
  • Keep flammable substances away from flame
  • Clean up smashed glass immediately
• What is the aim of paper chromatography in this experiment?

  To investigate the composition of inks
• What equipment is needed for paper chromatography?

  • 250 cm​3​ beaker
  • Ruler and pencil
  • Distilled water or suitable solvent
  • Chromatography paper
  • Pipette or capillary tube
• Why should a pencil be used to draw the line on chromatography paper?

  Pencil is insoluble and won't travel up
• What should be done with the ink spots on chromatography paper?

  They should be placed above the solvent level

  
• What is the significance of measuring the distance travelled by the solvent front?

  It allows calculation of Rf values
• What is the formula to calculate the Rf value in chromatography?

  $Rf =$$\frac{\text{distance moved by substance}}{\text{distance moved by solvent}}$
• How should the chromatography paper be treated after the solvent has moved?

  It should be removed before the solvent reaches the top
• What can be inferred if two ink spots have the same Rf value?

  They are likely the same substance
• What are the safety precautions for paper chromatography?

  • Wear safety goggles and gloves
  • Use a well-ventilated lab or fume cupboard
  • Clean up spillages or broken glass immediately