Red cabbage (Brassica oleracea capitata rubra) can be used as a natural pH indicator, its pigments change color in response to varying pH levels.
Pigments can be extracted from the leaves of red cabbage, and relative pH can be determined by adding drops of a liquid into the pigment, as noted in the following table:
pH 1-2 Pink/Acid
pH 3-4 Dark Red/Acid
pH 5-6 Violet/Acid
pH 7-8 Blue/Neutral-Base
pH 9-10 Blue-Green/Base
pH 11-12 Green-Yellow/Base
What can a student determine about the red cabbage solution as a natural indicator of pH?