Our experiment relates to scuba diving and The Bends because it demonstrates Henry’s Law and Boyle’s Law. Henry’s Law states that the more pressure exerted on a gas, the more it dissolves into a liquid, like in soda. In soda, there is carbonation. The carbonation is created when there is a large amount of air pressure in the bottle, forcing some of the air to dissolve into the soda. When you open the soda, you relieve the pressure, making the bubbles show in the soda. This can also happen to people. When a person dives down really deep underwater, there is atmospheres of pressure exerted on the body. Because the pressure is so great, it forces some of the nitrogen in the air breathed in to go into the blood stream. If the person comes up too fast, bubbles will be created in the blood stream. This is very painful, and is called Decompression Sickness. Boyle’s Law says that the more pressure on a gas, the smaller the volume. While scuba diving, you go down to different depths and breathe in air. Air is about 80% nitrogen and about 20% oxygen. If you took a breathe of air at a depth of 33 feet or 2 atmospheres, for instance, you would be breathing in more air than how much you would at the surface, or 1 atmosphere of pressure. As stated in Boyle’s Law, there would be much more pressure no the air so the volume would be smaller. If you took a breathe at 2 atmospheres and held your breathe while you rose to the surface, rose too fast, or stayed down too deep for too long, the air in your blood stream would expand causing you to get a disease called The Bends, or decompression sickness. When you rise, causing the air in you blood stream to expand, the bubbles start blocking capillaries and arteries. This is very painful and can even be fatal. The only to get the bubbles out of you blood stream is to go into a pressure chamber where a lot of pressure would be applied to your body and very slowly released. The whole process could take many hours.
In our experiment, we measured the effects of pressure on the volume of the carbonation that came out of a bottle of 7 up. Our first, more shallow depth, was even with the top of the window in the pool at Long Beach. Our second was even with the bottom of the window, and the third, our deepest, was on the bottom of the pool, 17 feet under. To measure the volumes of the carbonation, we opened the bottle of soda under a funnel that was attached to a clear plastic tube with a rubber stopper at the end. Before we dove with the experiment, we measured and marked at 50 ml, 100 ml, 150 ml, 200 ml, up to 600 ml by 50 ml at a time. At our first depth, the carbonation was 350, 250, 240, and 240 ml. We decided not to use the 350 because it was so different from the others and would change our percent of error considerably. With out the 350 ml, we had an average of 243.3 ml and only 2% error. At the second depth, we got an average of 236.7 ml and also had only 2% error. At the third depth, we got an average 193.3 ml, with an error margin of 12%. This shows that as pressure increases, volume decreases.
To find the percent of error for each depth, we did an error analysis. We had very little error in our experiment except for at the last depth. At the first two depths, we took our time and our experiment was working fine for the most part. By the time we got to the third depth, we were rushing and having trouble keeping our funnel and tubing securely connected. We think this caused much of the error. Also, we only measured at 50 ml intervals so we had to approximate the volume of the carbonation. We also had nothing to keep our experiment as well as us in place. We were drifting around a little, which caused there to be more or less pressure on the carbonation.
If we were to redesign the experiment, we would make our experiment more stable and measured more carefully. Our experiment was very flimsy and fell apart several times. We would have either found a different way to measure or secured the tube to the funnel better. Also, we did only measured at 50 ml intervals. It would have helped if we had done it at 10 ml intervals or some other smaller number. Also, we would make our whole experiment bigger because we ran out of room and it was very hard for us to measure.