Help your children make a bleeding red cabbage with a little vinegar, and then they can magically turn it green with some ammonia. Make sure your kids wear goggles and rubber gloves when using ammonia and vinegar. They should also avoid skin contact with ammonia. If ammonia gets on their skin, wash immediately with lots of water.
What You'll Need:
- 1/4 head red cabbage
- Measuring cup and spoons
- Glass bottle with cap
- Rubber gloves
- 3 test tubes (or glasses)
- Pipette (or eyedropper)
How to Make Bleeding Red Cabbage:
Step 1: Help your children cut cabbage into chunks. Have them put the cabbage into the saucepan with two cups water. Help them heat the pan to a low boil on the stove. Then turn off the heat, and let water cool.
Step 2: Help your kids pour the cabbage juice through the strainer into a pot. Make sure to use a funnel to pour the cabbage juice into the bottle. Then have your kids throw away the cabbage. Your kids have made the cabbage juice indicator.
Step 3: Have your children test their cabbage juice indicator. Make sure they put on their goggles and rubber gloves. They should put two tablespoons of the indicator into each test tube. Have them then add two tablespoons of water to each test tube to dilute the indicator.
Step 4: Your children should add a few drops of vinegar to the first test tube, a few drops of ammonia to the second test tube, and a few drops of water to the third test tube. (Make sure they rinse the pipette well between liquids.)
Step 5: Have your kids compare the color in each test tube. Afterward, they should keep the cabbage indicator in the refrigerator for other experiments. Boiling the cabbage let its pigment escape into the water. This pigment is pH sensitive. So when you added vinegar, it turned red. The cabbage indicator turns red in acidic solutions. When you added ammonia, it turned green. The cabbage indicator turns green in an alkaline solution.
Keeping the theme of colors in mind, keep reading science projects for kids: chemical reactions to learn how your kids can determine what black ink is really made of.