Understanding the pH Scale
The per Hydrogen Scale
This is a Design Challenge for Understanding the pH Scale. In this design challenge we will create Universal Indicator from red cabbage Anthocyanin. Then we will test seven different materials.
Build The Anthocyanin
Step one is to collect red or purple vegetables to make anthocyanin with. We used red cabbage, purple kale-and red lettuce. We chopped it and boiled it for three minutes. Then we drained the vegetable matter. Now we have anthocyanin. Let it cool before you use it!
Select Your Acids and Bases
We used a variety of materials, including:
Baking Soda
Vinegar
Purified Water
Coffee
Lemon Juice
Rabbit Urine
Hydrochloric Acid
Chicken poo
Be sure to label your materials and wear gloves! Pour 50cc of anthocyanin in each test bottle. Then ask the kids to anticipate if the material will be red, orange, green, blue, or purple. Add the materials, close the lid and shake.
When all the materials are added, let the materials rest for a few minutes. Have kids explore why the anthocyanin does this via Google. Have them develop a hypothesis on the color spectrum. If you want, write a small play about it!
