Red Cabbage Laboratory

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Red Cabbage Laboratory

• Sherene A. James
• Education Outreach Officer
• Natural History Division

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What makes red cabbage red?

• Chemicals inside the cabbage gives it a red colour

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Why can we use it in the lab?

• The chemical inside it causes other chemicals
  inside foods and other liquids to change colour

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How will we use it?

• We will use red cabbage to see if some foods and
  household chemicals are acid, base or neutral

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What does acid, base and neutral mean?
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Indicators

• An indicator is used to test if some thing is an
  acid, a base or if it is neutral

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How to Make Red cabbage Indicator

• You will need
• an adult to help you
• one red cabbage
• water
• a hot plate or stove
• a cooking pot
• NEVER DO THIS EXPERIMENT ALONE, ASK YOUR PARENTS
  FOR HELP!

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How to Make Red cabbage Indicator

• Shred half of the cabbage and place it in the pot
• Add 2 cups of water
• Boil for 10 minutes (be very careful)
• Let the liquid cool

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What can you test with your indicator?

• bleach
• syrup
• orange juice
• apples and apple juice
• vinegar
• home cleaning products
• coffee
• tea
• and much more!

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What you will need for your test

• disposable cups or bottle caps spotting tiles or
  test tubes
• permanent markers
• a sheet of paper for recording your results

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What will we test?

• Label your spotting tiles or test tube or bottle
  cap (use the first letter of the item to be
  tested)
• Put a small piece or a small drop of your test
  item on the tile/bottle cap/test tube
• Drop a small drop of red cabbage juice on each one

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What did you see?

• A red colour change indicates ACID
• A green colour change indicates BASE
• No change indicates NEUTRAL
• Test some water and see what happens

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Draw a table like this and note your results
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How to make indicator Paper

• Soak a coffee filter in the cooled red cabbage
  juice
• Remove and dry
• You can now use your indicator paper whenever you
  want to know if something is acid or base