 Rock Street, San Francisco

This lab allowed us to see just how much copper coating was used in a particular penny. Not knowing he about information, my original hypothesis was that the penny would contain a great deal of pure copper. The following report will walk you through my actual findings. Our lab consisted of three parts: determining the proper wavelength for the spectrophotometer, constructing a calibration curve for Cue(NH)42+, and finally determining the actual content of copper in a penny.

IN the first step of the lab, we used water to calibrate our spectrophotometer, and then measured the absorbent of Cue(NH)42+ at different wavelengths, in order to determine the optimal one. In our group, we determined Mann was the optima wavelength with an absorption of 1. 32. The chart below shows our absorption rates: We then went on to part two, where we used the optimal wavelength to determine a calibration curve for the absorbent of Cue(NH)42+.

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We took varying levels of a Cue+ solution and added it to ammonia an looked at the absorbent amounts, which are seen in the below graph: With parts one and two of our lab complete, we now know the optimal wavelength to measure absorption at and we have determined absorption levels of Being that we followed the Beer-Lambert Law that concentration ND absorption are related, we were able to look at the absorbent levels of light through Cue(NH)42+, and now in part three determine the amount of copper a given penny may contain.

We collected data from a 2005 penny in our group. IN order to find the average absorbent, we added HON.. To the penny and allowed a violent reaction to take place in which the penny dissolved completely displaying blue and reddish brown coloring. We obtained a flask with distilled water and added our penny solution. We then took a portion of the penny solution and added a small amount of ammonia and used this solution to check he absorbent amount.

We completed this process three times to gather an average absorbent amount for our penny. The following chart will show our findings: The results show above show that … V… This is acceptable because….. We went about the experiment this way because…. As you can see in these graphs… What took place in this lab was this chemical reaction which helped us get to our final result. … 