(Submitted by CHS Junior, Kellie Waugh)
          In Advanced Biology, over the course of the past week, we students have conducted a lab observation including an egg to learn about diffusion. This experiment had three main steps to it. The first step was placing a normal, straight-out of the carton egg in vinegar to let soak for a few days. The class made hypotheses about what the outcome would be from soaking the egg. After two days of the egg soaking in the solution, we observed the egg, and the vinegar, and recorded what we saw. We then conducted these exact same practices twice more, in two different liquids; maple syrup, and distilled water, using the exact same egg for the entire lab. Each time, letting the egg soak in the liquid for a few days, writing a hypothesis of what we think the outcome will be, and then observing the outcome and comparing it to our hypothesis. Through comparing the outcome to our original predictions, we learned to reason why the egg reacted to the liquid as it did.             As for the outcome of each soaking; first off, the process states that things of higher concentration diffuse to points of lower concentration. This law proved true for the entire lab. When soaked in vinegar, the egg’s shell changed states, due to a reaction of the makeup of the shell, and the acidity of the vinegar. The shell changed from a solid to a foamy liquid floating on top of the vinegar. Due to the solid shell changing states, this left only the membrane to keep the egg intact. We observed that the membrane was semi-permeable, meaning the vinegar would diffuse into the egg due to concentration differences, and not let it leave, causing the egg to swell and grow in size. Next the egg was washed off and soaked in maple syrup. The maple syrup is made mainly of three ingredients; water, sugar, and some food coloring. It was obvious through observation that the vinegar in the egg diffused out, and the food coloring went into the egg, all due to concentration differences. This caused the egg to become shriveled, and darker in color, and the syrup around it to become lighter in color. Lastly, the egg was washed off and soaked in distilled water. Yet again, because of the differing concentrations of the liquid inside the egg, and outside of the egg, the water diffused into the egg, causing it to grow in size, and the food coloring diffused out of the egg. This caused the egg to become lighter in color, and the fluid around it to become slightly darker.                  The outcome of soaking the egg presented a new excitement for observation every few days. Watching the egg change, in size and color, made the class eager to learn about why the changes took place. The purpose of the diffusion lab, was obviously learning about the diffusion, and we did just that. Each time we observed the egg, we discussed how diffusion affected the egg’s circumstance/outcome, as well as how diffusion may occur in the next soakings of the egg. This lab taught the class not only about diffusion and how that occurs, but also about the importance of observation and justifying your hypotheses.

Mr. Mack