Question

red cabbage color changes with ph
ph
color red light pink dark pink purple blue aqua green yellow
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.
solution a solution b
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
2)__ solution b could be classified as
a. basic
b. acidic
answer the question.

1. how do you think red cabbage (specifically the chemical anthocyanin) can be used to indicate whether a solution is acidic or basic? hint: think about the chemical process that describes how an indicator works.

Explanation:

1)

The color code shows purple corresponds to pH 6.

Solution B is blue; blue corresponds to pH ≥8 (basic range).

Anthocyanin changes structure/color with pH. In acidic conditions, it takes H⁺ (red/pink); in basic, donates H⁺ (blue/green/yellow).

Answer:

B. 6

2)