Week Seven

    The beginning of this week saw the completion of our final proposal rough draft. Liz, our teaching assistant, told us that first and foremost, we should display the most current table of values for the tests that we did in our report. After we created graphs from our lab notebook in Microsoft Excel, we began testing the electrochemical cell and obtaining more values. The copper II sulfate came in the mail, so we were able to test the cells with this. We only did basic tests during lab, to see if there would be an increase in current and any affect on electric potential. We planned to get a chart of values later in the week during our team meeting. During this general test, we observed a substantial increase in current, and a small decrease in electric potential. We also observed a rapid deterioration of the aluminum metal. This was an initial thought during the start of the term that we knew could pose an issue later on. By increasing the current, we are increasing the reaction, and therefore using up the reactants more rapidly. Within five minutes, the aluminum was already brown with copper product. We have to be careful about this, because if enough of the reaction occurs, it can substantially affect our current and potential.

    Friday the team met to test the concentration of copper II sulfate and the affect it has on the current and voltage. We tested the cell with 1.25 mL of copper II sulfate, and then increased the concentration in increments of 1.25 mL. We found that there was a large increase in current, and a slow fall of potential. The maximum current from the cell was about 16 microamps.

    On Monday night, Rich tried to get the motor to work with the electrochemical cell. He tried with multiple cells, and could not get it to work, even with the large increase in current. We discussed the options for our second deliverable this week, and decided that it would have to be the boat with the cell inside of it. We had hoped to get the motor working, but for now we have to go without it.