Question

activity: the many shades of red cabbage
as you work through the following exercise, use the ph scale to help answer the questions.
red cabbage color changes with ph
a student is interested in creating a food - based ph indicator. although familiar with the electronic ph meters and test strips, the student wants to know what food product could be used as a suitable ph indicator substitute. after researching the subject, the student decides to use red cabbage as the food product.
there is a chemical in red cabbage called anthocyanin that changes color depending on the acidity of the environment. the cabbage indicator was used to test the acidity (and basicity) of two different solutions. the solutions turned the following colors after the cabbage indicator was added:
choose the best answers.

1. ____ looking at the color code at the beginning of the activity, solution a most likely had a ph of

a. 10
b. 7
c. 12
d. 4

Explanation:

The color chart shows red cabbage turns purple at pH 6. Solution A is purple, so its pH matches this value. Among the options, B (7) is closest to neutral pH 6 (likely a rounding or chart approximation).

Answer:

B. 7