Acid/Alkalis Dyed T-Shirts and Lemon Powered Clocks
Experiment Preparation:
You will need to prepare this indicator solution in order to perform the acid/alkali experiment.
Chop up a red (it's really purple) head of cabbage.
Boil a large pot of water on the stove and add the chopped cabbage.
Stir the mixture.
Turn off the heat and allow it to sit for 30 minutes or so...Once I forgot about it and left it on the stove for several hours and it still worked.
Pour the cabbage water through a sieve and into a bowl.
You can store your cabbage indicator in the refrigerator in a two liter bottle...just make sure no one thinks its purple soda.
Add some polish sausage and onion to the cabbage and eat it for dinner. Just the cabbage, not the juice!
You are now ready to do some really neat acid/alkali tests.
Add 2 Tablespoons of alum to your cabbage juice. Heat the mixture on the stove until it is hot. Let the kids stir in their T-Shirts. Let them soak in the hot mixture for about a half an hour.
Now squeeze out the shirts and lay them on newspaper. You may want to stuff the shirt with a trash bag so you can work on both the front and back of the shirt. Otherwise the color will bleed through on both sides.
Have the child squeeze on, pour on, or paint on the lemon, lime, milk, baking soda and what ever else you are going to test. Have them try to keep the areas separated on the shirt so they can see the reaction.
Cabbage juice is an indicator liquid, which means it will always turn pink when touched by an acid and will always turn blue or green when touched by an alkali.
The cabbage juice will turn the baking soda water blue or green since baking soda is an alkali.
The cabbage juice will turn the lemon pink since lemon is an acid.
The water will just be purple since it is neutral (not an acid or alkali).
Don't wash the shirt right away, or the colors will really fade. Wait a week or so and then wash them in cold water.