Red Cabbage and Acids

Teacher chopped red cabbage and put boiling water on top. The colour from the cabbage went into the water. We put this water into cups. We tried adding lemonade to one cup and wash up liquid to another. Both cups turned pink because of the acid. Soap turned the cabbage water a blue green colour so we know this soap is alkali.

Lemon turned the cabbage water pink. Lemon is acidic.

Our acids all turned the cabbage water pink or red. Our alkalis all turned the cabbage water blue or green.