A red cabbage acid test is a fun and easy experiment that you can do at home to learn about acids and bases. It uses red cabbage juice as an indicator, which means that it changes color depending on the pH of the substance it is mixed with.
pH is a measure of how acidic or basic something is. It is measured on a scale of 0 to 14, (7 is neutral, anything lower than 7 is acidic, and anything above 7 is basic).
*This experiment requires parental supervision!
To do a red cabbage acid test, you will need:
- 1 head of red cabbage
- A knife for chopping the cabbage
- A blender
- A large bowl
- A strainer
- A few cups
- A dropper or spoon
- A variety of different household items to test, such as: vinegar, baking soda, lemon juice, milk, water
- Chop the red cabbage into small pieces.
- Add the chopped cabbage to the blender.
- Add enough water to cover the cabbage and blend until smooth.
- Pour the blended cabbage into a large bowl.
- Place a strainer over a glass or cup.
- Pour the cabbage juice through a strainer to remove the solid pieces.
- Discard the cabbage leaves.
Now you are ready to test!
- Add a small amount of each test liquid to a separate cup.
- Add a few drops of the red cabbage juice to each cup.
- Observe the color change
The color of the red cabbage juice will change depending on the pH of the liquid it is mixed with. Here is a guide to the different colors you might see:
- Acidic liquids will turn red or pink.
- Basic liquids will turn green or yellow.
- Neutral liquids will turn purple or blue.