Following up on the conservation of matter lesson from yesterday, students worked in groups to conduct a similar experiment to the baking soda and vinegar demonstration. Today, students were tasked with experimentally testing the law of conservation of mass by mixing known masses of vinegar and Tums (calcium carbonate), then capturing the carbon dioxide released in the experiment in a balloon placed over the flask. They were tasked with determining how much carbon dioxide is produced but the challenge was that, unlike the demonstration yesterday, they could not simply allow the carbon dioxide to escape into the atmosphere. After much trial and error, students gained practical experience working with various pieces of glassware, reagents, the digital balance, thinking through order of experimental operations, recording observations, and sharing their understanding of what was happening during the chemical reaction. We concluded with a discussion of the chemical reaction (pictured below). Students will meet tomorrow in the library computer lab to compile their findings into a lab report. Students were encouraged to take pictures or video into their investigation today and those can be incorporated into the lab report.
Daily Archives: September 24, 2015
Cells & Homeostasis: Egg Lab Data Day 3
On this third day of data collection for the egg lab, students observed their eggs after 24 hours in the liquid they chose yesterday. Students once again gently rinsed their eggs and cups, then measured and recorded the mass. The eggs were placed back in the cups and then filled with tap water for one final day. Students shared out their egg mass data and we began crafting a model to help fit their observations. We focused on the eggs in corn syrup (they shriveled) and in distilled water (several popped), with students beginning to reason through what may have entered and left the egg across the cell membrane. We concluded with students receiving the Friday quiz to work on as homework and to help them focus their reading from the packet that went home yesterday. Students who complete the quiz as homework will have the opportunity to boil their egg in class tomorrow and observe the process of an egg boiling without a shell.
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