Chem Blog Week 9

This week in class, we learned how to measure atmospheric pressure using a barometer we had to make for a project, and how to mathematically find the pressure, temperature, volume, and number of particles.

We previously learned that a barometer measures atmospheric pressure. During the past weekend we were told to make one out of household materials. I used the more common model, (a jar with a balloon on top and a straw) but I made it to work efficiently by including a guide and a stand for the barometer.  Mr. Abud really liked mine and he did so much that he tweeted it!

We later went outside to experiment with our barometers. The moment we went outside my barometer began to react to the increase of atmospheric pressure. The needle went up outside because of two factors: temperature and pressure. Since it was cold outside and there weren't many clouds in the sky, this meant that the cold air, denser than the warm air, pushed down on the warm air, or the warm air remained above the cold air. Thus, air pressure increased. Since it was cold outside, I figured the cold air pushed down, but not necessarily on the warm air. It may not have pushed down on the warm air because it is possible that the water evaporated because the air was warm enough to do so, and then the clouds condensed before the cold air pushed down. Even in my car on the way to class, the pressure was measure being low because the heat was on so I was really excited that I kind of learned something before the class did. I also noticed that the needle on the barometer went up because the colder air exerted greater pressure on the balloon, thus accounting for the increasing downward force. Then, as the balloon is pushed downward, the needle goes up because of the elasticity in the balloon providing a counter upward force (torque) to lift up the balloon at the point where the balloon dips. I also learned that as we went inside, atmospheric pressure went down, since the atmosphere inside is mostly warm air. Therefore, the decreasing pressure pushing onto the balloon causes the needle to go down.

This week, I also learned how to do mathematical problems involving temperature, volume, number of particles, and pressure. I learned that the secret to do these problems is to keep in mind that when you are trying to find the change of one of the factors, you have to make that you keep them proportionately related to each other. I am a little bit shaky on this but hopefully I should be able to understand it next week.

This week was slightly complicated because I am actually in St. Louis typing this “rough draft” of my blog because the hotel has terrible Wi-Fi and I won’t be able to send it to you! So I’m sorry in advance for this being late. Hopefully I should be able to catch up on what I missed on Friday.