Natural pH Indicator - Talia, Maggie, Katy, Allison, Claire


In our lab, we used carrot juice to as a natural indicator. Indicators turn different colors in solutions of different pH values by chemically reacting with hydrogen if an acid or hydroxide ions if a base. We first added carrot juice to substances with known pH values to determine what color the indicator will turn the substance at all different levels of pH. We then dropped carrot juice into multi-purpose cleaner, nail polish remover, bubbles, and dish soap, to compare the color they turned to the knowns and figure out if they are an acid or a base. An acid is a chemical substance that neutralizes alkalis, while a base is a chemical substance that accepts protons to increase the hydroxide concentration (OH-).


Color for Acids - orange

Color for Bases - orange

Our indicator was not effective in texting acids or bases; both turned out to be orange with barely any visible variance in color. The main issue we encountered was that all of the substances turning the same shade of the same color disabling us from telling what was an acid and what was a base. If we were to do this experiment again, we would make sure that the carrot juice is fresh, and possibly boil the carrots to get the extract -- as we did with the red cabbage -- as opposed to juicing them. However, we feel as if carrot juice may not be the best choice of natural indicator and would therefore prefer to use a different choice.

Works Cited

  • Acids and Bases. (n.d.). Retreived June 01, 2016, from

  • What household substances can be used as acid/base indicators?. (n.d.) Retrieved May 28, 2016, from