Do the Acid or Alkali Cabbage Experiment

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We recently came across this cool, easy science project that lets you work out the acidity of anything using red cabbage!

Whenever we want to measure how acidic or basic something is, we use the PH scale.

The PH scale goes from 0 – 14. Anything less than 7 is acidic, anything greater than 7 is alkaline (or basic) and if it has a pH 7 then it’s considered neutral!

For example, Lemon Juice is acidic, water is neutral and toothpaste is alkaline.


So where does red cabbage come into this?

acid-and-alkali-cabbagetBasically red cabbage has a very cool power where it can tell the acidity of other substances. All you need to do is the following:

1. Chop up cabbage and soak in water

2. Once the water has turned purple add some to 2 plastic cups

3. One of these cups is your ‘control’ for comparison and the other is your ‘experimental’ cup

4. Add a household substance such as cola, lemon juice, ketchip, soap, vinegar or toothpaste to the cup

5. Give it a stir and watch the colour change!

What should you see?

The more acidic something is the more pink the red cabbage water will turn.

The more alkali it is the bluer it will go.

And if it stays the same then it’s neutral!

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