Add enough of the bromthymol blue indicator solution to each bottle to obtain a green color (about 2–3 mL). BTB should be green in color. Add either a few drops of acid or base to adjust the pH of the ...

Beets, and other fruits and vegetables like blackberries, plums, and blueberries are natural indicators of pH. They have a compound called anthocyanin that gives them both their pigment and this ...