Cherry as a Natural Indicator

By Ryan G, Sami W, David N, and Devin T

Introduction

The purpose of this lab was to determine which household substances were acids or bases using a natural indicator. Indicators change color in the presence of an acid or base, and the color indicates the pH value. An acid has pH lower than 7 and dissociates to create a hydrogen ion, and a base has pH higher than 7 and dissociates to create a hydroxide ion. The household substances we will test are Febreeze, Tide, vinegar, Green Works, and Shout. We predict that the vinegar will be an acid, and the other four will be bases.

Procedure

The following pictures show the procedure we used in this experiment.

Data

The following pictures show the data we determined after conducting our experiment.

Conclusions

When conducting this experiment, we learned that using cherries as an indicator was not very efficient. The pH value solutions did not differ in color a very noticeable amount, which made it difficult to determine the exact pH value. They were all red, while the acids (pH 1, 3, and 5) were lighter red, and the bases (pH 9, 11, and 13) were slightly darker red. Due to the small range of colors, and our indicator being darker more often than not, we determined that it is better at detecting bases than acids. We struggled to determine the pH values of any acids, because our indicator was very dark to begin with, which caused the substances to always appear to be closer to the base's colors, even if they were supposed to be acids. Also, our indicator solidified a bit in the time between mashing up the cherries, and actually using it, so that made it difficult to use. If we were to do this experiment again, we would have to mash the cherries much closer to the time when we are actually using the indicator.