Red cabbage indicator

• 1. Take two leaves of red cabbage. Tear them into pieces and put them in a 250cm3 beaker
• 2. Cover with distilled water and place the beaker on a wire gauze on a tripod. Light the bunsen burner. Warm the mixture and stir with a glass rod. The water will extract most of the colouring from the red cabbage and turn purple
• 3. Decant the coloured solution into a clean beaker. This is the indicator
• 4. Fill three test tubes with HCl, NaOH and H2O
• 5. Using a pipette, add the red cabbage indicator and stir. Record the results.
• Risks:

  • glass breaking
  • explosive chemicals if mixed
  • bunsen burners
  • hot equipment
  • wear safety glasses
• Red cabbage turns red/pink in an acidic substance
• Red cabbage turns yellow/green in an alkaline substance
• Red cabbage turns purple in a neutral substance