Monday, January 20, 2014

Blog Entry 1/19/14

This week in AP chemistry was filled with much more exciting experiments than usual. In class, we performed the experiments many people expect out of a chemistry class: freezing random things, harmlessly setting students’ hands on fire, and freaking out random passerby by pouring suspicious substances near them. On Thursday and Friday, we performed many demos with said suspicious substance: liquid nitrogen! I have to say this was probably one of my favorite weeks in chemistry; learning about a reaction is one thing, but seeing it in action is just plain cool.

We started off the week by completing a few more lecture quizzes on Kinetic Molecular Theory and partial pressures. Recently, we have been starting to participate in ConcepTests as a class much more frequently. Of all the ways we use to go over material in class, I think I’ve found ConcepTests most helpful. Although I find whiteboarding helpful, I sometimes don't have time to finish all of the problems before we go over them, which makes me become confused and a little overwhelmed when we move through each group’s board and their process quickly.

ConcepTests allow for a little more independent thinking. We are given a question on the projector, and asked to think about it and hold up the fingers that correspond to the answer we choose. It’s kind of like a voting system, and it’s very interesting when the class comes up with a broad spectrum of different answers. After voting individually, we discuss the question as a group and agree on one answer. I really like this system because I have to process and solve the question on my own before talking with my group mates. I am able to reach an answer myself without coasting on someone else’s answer and just agreeing with it.

After discussing the question, we go over the question as a class and Dr. J makes sure all of us understand the process used to reach an answer. I don’t ever feel left behind when we use this method, and I feel much more involved in the class.  

The most exciting part of the week was undoubtedly the liquid nitrogen demo. There were many collective “ooohs” and “aaaahs” as we froze objects to our hearts’ desire. We started off with a bouquet of flowers, and went to freezing grapes. We however were not satisfied there, oh no! We continued freezing miscellaneous objects from squash balls to marshmallows. We even froze money! Talk about some pretty cold currency.  I had a frozen marshmallow herself due to my extremely good luck being picked in the Chemistry Volunteer Lottery. Most of my classmates lingered afterwards to try a marshmallow of their own, so of course everyone went home happy.

This demo was not just fun and games, however. We discussed much of the science behind the substances and the behavior of the molecules involved. In one demo, we boiled water by using ice, and little droplets of liquid oxygen condensed on the desk.

The day after we played with something leaning more on the hot side: fire. We bubbled methane over water and some students picked up a handful of large methane bubbles, which were then promptly set on fire by Dr. J. The smell of charred hair might have filled room B403, but it’s not everyday when you get to set your hands on fire and emerge unscathed.

This week in chemistry was a lot of fun, while still being able to be a learning experience. I’m hoping to perform more demos in the future in class!


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