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Kitchen indicator: red cabbage

Red-cabbage juice changes colour in acids and in bases.

Topic: First chemistry (grades 7–8)Grade: 8Free

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What you do

  1. Add vinegar (ethanoic acid) to tube 1: acids turn it red-pink.
  2. Add washing soda (sodium carbonate) to tube 2: bases turn it green-blue.
  3. Leave tube 3 as it is (neutral, purple) and turn on the pH meter to compare.

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