Blackberry Indicator

by Hillary, Nicole, Kate, Emily, and Sara


The purpose of this lab is to use a natural indicator to test the pH of household substances. An indicator is a substance that undergoes a distinct observable change when conditions in its solution change. The Change in color indicates the pH value of the solution. A base is a substance that is slippery to the touch, taste bitter, and turn indicators blue. An acid is a substance that is typically sour, and turns indicators red. The household substances we chose to test are Sierra Mist, laundry detergent, corn syrup, and shower cleaner. We believe these will be acidic, basic, basic, and basic respectively.
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To make our indicator, we put the blackberries in a blender and then strained them to ensure we were left with only liquid.

Determining color range

We determined the color range for our indicators using pH standards of 1,3,5,7,9,11,13.

Household substances

all of our substances started off clear and after mixing in our indicator, we saw the color shift, telling us the pH


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We learned a lot throughout the process of using the blackberry as an indicator for our project. Blackberries, when mashed, create a very thick, dark red, liquid. Because the indicator is not a liquid, it was harder for the indicator to mix with the other substance to create one color. The test tube consisted of a very thick solution and most of our tubes looked a dark red - purple color. In past labs, we worked with substances that were not natural, so the two liquids were easy to mix, but because the blackberry is a natural substance, it was harder to create one liquid.

Our indicator was better at detecting bases than acids.

While using our natural indicator there were a few problems. We blended blackberries and the result was a very thick consistency. When we went to add drops of the indicator to the household substances it was a little hard to get the indicator into them. Our indicator stayed at the top of the test tube while the household substance was still at the bottom. Over time, the indicator spread out and allowed us to see the new color but it still wasn’t as accurate as it could have been. When we were judging the pH’s some of were very similar in color. We named them the best we could but it still left room for error. If we were to do this test again, adding more water to thin out the indicator would be beneficial.