Creating An Acid-Base Indicator

For my project, I had to create my own acid-base indicator and find out what happens when it is placed in an acidic solution (vinegar) and a basic solution (dissolved baking soda). I chose my indicator to be a fruit because fruits can be very effective at determining how acidic or basic a substance is. My fruit was a blueberry, but I couldn’t use raw blueberries because it’s not going to give me the best results. I had to make blueberry juice. I did this by placing several blueberries in a blender with some distilled water. I used distilled water because it doesn’t have any vitamins or minerals that could possibly interfere with my results. Then, I turned the blender on, and I got blueberry juice. I had to strain the juice to remove all the
chunks of blueberry because the chunks aren’t needed. Then, I used my new indicator to see the color change in an acid and a base. To sum up, I created my indicator by placing blueberries and distilled water in a blender to make juice, and then I strained it to get all of the chunks out.

Before, I can mention what were the color changes, it’s important to understand what my indicator is and how it works.
My indicator is an acid-base indicator. Acid-base indicators are substances that have some kind of change in their properties (usually color) in the presence of various different acids or bases due to some chemical change. The purpose of an acid-base indicator is determine whether a substance is an acid, a base, or just neutral. One popular acid-base is litmus paper. Red litmus turns blue in a basic solution and stays red in an acidic solution. Blue litmus paper turns red in an acidic solution and stay blue in a basic solution. As you can see, litmus paper changes color in the presence of acids and bases, and this allows us to infer whether or not a substance is acidic or basic. Another indicator is red cabbage juice. Cabbage juice will turn pink when an acid is present, and it will turn blue when a base is present. Anthocyanins are the chemicals responsible for the color change in cabbage juice in different solutions due to a gain or loss in hydroxide ions (OH-). My blueberry indicator works in an extremely similar way as the cabbage juice. In conclusion, acid-base indicators will have some kind of change to their properties (mostly color) when in the presence of an acid or base due to some chemical
change.

Blueberry juice is a great indicator, and it works very similar to cabbage juice. Anthocyanins are found in blueberries, and they are responsible for a blueberry’s color and any color changes. One specific anthocyanin in blueberries is malvidin. Malvidin is one of the several anthocyanins responsible for the blue color of blueberries as well as the color changes blueberry juice undergoes when an acid or base is present. Then, I needed to run an experiment to find out what the color changes will occur when blueberry is placed in an acidic solution and basic solution. First, I had to set up the experiment. I made my blueberry juice as described earlier. Then, I dissolved some baking soda in distilled water because the powder is useless in this experiment. This baking soda solution would represent my basic solution. Later, I got some vinegar, but the vinegar I had was extremely strong and thick. I used my distilled water to dilute the vinegar to slightly make sure that it would have a similar concentration of hydrogen ions to a less thick version of vinegar. Obviously, these solution were placed in cups I had at home. Then, I simply poured a small amount of cabbage juice into each of the cups. When I ran the experiment, there were distinct color changes when I placed some blueberry juice in the diluted vinegar and dissolved baking soda. The vinegar turned red, and the dissolved baking soda turned dark green or dark blue. To sum up, many fruits and vegetables can be acid-base indicators that will change color when in the presence of an acid or base, and it’s very easy to find out this color change at home by using vinegar and baking soda.