Monday, January 3, 2011

We began class today by passing out our lab notebooks, old papers, as well as a graph and the new unit packet. The next unit is Thermochemistry. We then discussed the last test. The results were unfortunatley not so great and Mr. Henderson gave us the option to come in to review the test. As an opportunity to help our grades, there are bonus points if the Webassign due the 13th is completed before the due date. For the Webassign, questions 1-6 need to be completed by Friday January 7th; 7-10 by Monday January 10th; 11-15 by Tuesday January 11th; and 16-19 by Wednesday January 12th. Tonights homework is a Webassign Reading Sheet on 8.1 due Tuesday.
We then began a new lab (TC1) called Zeroing in On Heat Lab. The purpose is to describe and explain the temperature changes experience by two objects of different temperatures when place din close contact with one another. In order to do this, we marked the temperatures of hot water and cold water every 10 seconds. We made a graph and the times started at 0 and went to 190. The temperatures for hot water (in celcius) were 84.6, 81.6, 75.2, 69.1, 64.9, 62.9, 59.3, 56.0, 51.8, 51.8, 51.3, 50.8, 50.2, 50.0, 49.7, 49.7, 49.4, 49.2, 49.0, and 48.9. The temperature of the cold water was as follows: 7.3, 17.8, 24.7, 28.3, 32.7, 37.8, 39.3, 43.4, 46.1, 47.0, 47.9, 48.3, 49.5, 49.5, 49.7, 49.7, 49.4, 49.2, 49.0, and 48.9. We then graphed our results, which should look something like this:

There is a line through 140 because that is when the hot and cold temperatures were equal. We then made our lab conclusion, which described how the temperature changes over time for both sets of data. My results were that the temperatures are inversely proportional until 140 seconds have passed. The difference between the seconds decreases over time. At the end, the released the same temperature. This constitutes a heat flow (exchange of energy). The hot warms up the cold and continues until they are at the same temperature. The graph should be taped into the lab notebook. Mr. Henderson also mentioned that there is a quest on Wednesday January 12th.