RP2

• DCPIP


  Redox indicator dye that turns from blue to colourless when reduced and accepts electrons
• Vitamin C


  Antioxidant that decolourises DCPIP in its presence
• Measure vitamin C content of fruit juice

  Use decolourisation of DCPIP
• Equipment


  • DCPIP solution
  • Vitamin C solution
  • Fruit juices
  • Test tubes
  • Pipette
• Procedure


  1. Transfer 1cm of DCPIP solution into a test tube

  2. Add Vitamin C solution dropwise to the DCPIP solution, shaking after each drop

  3. Record the volume of Vitamin C required to change the colour of the DCPIP

  4. Repeat the experiment replacing the Vitamin C solution with fruit juices
• Hazards


  • DCPIP - Irritant to skin and eyes, may cause staining
  • Broken glass - Cuts from sharp object
  • Bags/stools - Tripping
• Safety precautions


  • Wear eye protection, keep away from edge of desk
  • Take care when handling glassware, keep away from edge of desk
  • Keep under desks and away from workspace
• In emergency


  • Wash from skin/eyes immediately using cold water
  • Elevate cuts, apply pressure, do not remove glass from wound, seek medical assistance
  • Seek appropriate medical assistance, clean spillages
• Plot a graph of absorbance against ethanol concentration/temperature