Active Time
20-30 minutes
Total Project Time
45 minutes to 1 hour
Key Concepts
chemical reaction, acids, bases, pH indicator
Four glass jars contain cabbage juice of different colors

Introduction

What if you could take a single liquid, and change it into a rainbow of colors without using food dye. You can! In this activity you will use red cabbage to make what is called an indicator solution. Indicator solutions can change colors depending on what you add to them. In this case adding something acidic (like lemon juice) will change it to one color while adding something basic (like bleach) will change it to another. Try and see how many colors you can make using different household acids and bases.

Credits

Teisha Rowland, PhD, Science Buddies
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.

Materials

  • A small red cabbage
  • Lemon or lime juice
  • Vinegar
  • Optional: Other foods to test, such as clear soda pop, baking soda solution, egg whites, tomatoes, cottage cheese
  • Small white paper cups, drinking glasses, or small white dish (at least 3)
  • Grater
  • Strainer
  • Optional: Large spoon
  • Boiling pot of water
  • Large bowls or pots (2)
  • Bleach cleaning product
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Active Time
20-30 minutes
Total Project Time
45 minutes to 1 hour
Key Concepts
chemical reaction, acids, bases, pH indicator
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