Ever since I was a kid, which I still am, whenever I got sick, my mom would always give me either Pepto-Bismol of a mixture of baking soda and warm water. Until a few months ago I never thought much of it, but when this year’s science came around and I needed an idea, I started wondering: “If Pepto-Bismol and Baking soda seem to have the same neutralizing effect on the acid in your stomach, what would happen if I put the Pepto-Bismol in some vinegar? Would it foam up like the baking-soda-and-vinegar solution?” I already knew that the reaction between the vinegar and baking soda was a basic reaction between an acid, the vinegar, and a base, the baking soda. I felt pretty sure that Pepto-Bismol had some sort of base in it too, so it would react, so I put my hypothesis to the test.
From my research, I found that the chemical formula for baking soda is NaHCO3, and that the formula for vinegar, or at least the acetic acid in it, is CH3COOH. I also found the formulas for the main chemicals in Pepto-Bismol, C7H5BiO4, and for Tums, CaCo3, which I also intended to try adding to vinegar. Another thing I learned during my research is that the chemical reaction between the vinegar and the baking soda is not one, but two steps. The first step consists of the atoms rearranging from NaHCO3 and CH3COOH to form CH3OONa and H2CO3. I was quite surprised when I found this out.
The materials for the experiment were as follows: twelve chewable Pepto-Bismol tablets, seven Tums chewable tablets, a tablespoon measurement, a tablespoon of baking soda, one and one half of a cup of vinegar, four four-ounce containers, a digital camera with four megapixels, a large glass bowl, a metal spoon, a metal whisk, a timer, a measuring cup, twenty four drops of blue food coloring, and a mortar and pestle. Once I had gathered all the objects, I began the experiment. First, I placed all twelve Pepto-Bismol tablets into the mortar, and began to grind them with the pestle. Once I was confident that it was thoroughly ground, I measured off one tablespoon of it, placed it in one of my four-ounce containers, and set it aside. Before I ground up the Tums, I had to wash the mortar out, but once I did, I placed all seven of the Tums tablets into the mortar, and began to grind. Again, once I finished grinding it, I measured off one tablespoon off, placed it in a four-ounce container, and set it aside. After the whole ordeal of grinding was out of the way, I got the measuring cup, measured one half of a cup, poured it into one of the four-ounce containers, and set the container in the bowl. Then I put eight drops of the blue food coloring into the vinegar, and stirred it with my spoon. After that, I placed the baking soda in the vinegar, taking pictures all the while. I recorded what happened, and then repeated the process of measuring, moving, coloring, and adding things to the vinegar twice, once for the Pepto-Bismol, and once for the Tums, adding slight variations such as stirring, in order to coaxes a reaction, and timing how long it took for the precipitate left in the liquid to settle. My mother, who was helping me, decided to taste all three of the concoctions too.
As for the results of my experiment, the Pepto-Bismol turned out to have a very unexpected reaction. In fact, there wasn’t much of a reaction at all until I stirred it thoroughly with a whisk, and even then, it produced very little foam, although the foaming lasted for around four minutes, and the precipitate left in the solution took two hours to settle. The taste and smell were wretched, a sweet, yet sour taste that made me gag. The sourness must have been due to left over acid. This reaction is not what I expected at all. The Tums’ reaction was rather surprising too. At first, it didn’t do anything, so I tried stirring it with a spoon. All of a sudden, it started foaming, slowly, but surely. The foam produced was oddly stiff and little clumps of un-dissolved powdered Tums hung, suspended within and throughout the stubborn bubbles. This solution too had a precipitate in it that took about thirteen minutes to settle to the bottom, and the end result had a strong vinegar-and-mint taste to it that was nowhere near pleasant. There was still a sour acidy taste to it, so I know that it too didn’t neutralize much of the acetic acid in the vinegar. As far as the reaction between the ever so clich vinegar and baking soda, all went as expected, a small outburst of angry foam, only lasting a few seconds, however, when my mom tasted it, it was very mild. It tasted like weak salt water, and all the sourness was gone, meaning that a lot of the acid in the vinegar was neutralized.
