Red cabbage juice can be used to test the pH of common household chemicals. From left to right, the colors result from lemon juice, natural red cabbage juice, ammonia, and laundry detergent.
An acid-base indicator is either a weak acid
or weak base
that exhibits a color change as the concentration of hydrogen (H+
) or hydroxide (OH-
changes in an aqueous solution
Also Known As: pH indicator
Thymol Blue, Phenol Red and Methyl Orange are all common acid-base indicators. Red cabbage
can also be used as an acid-base indicator.