Regarding The Spectrophotometric Analysis Of A Copper Penny
Introduction:
The main objective in this experiment is to determine if the claims made by the US government, regarding the spectrophotometric analysis of a copper penny hold true. Before 1982, the Lincoln cent contained 95% copper and 5% various mixtures of zinc and tin. As the cost of copper increased, the cost to produce the penny was more than the actual face value of the penny. This caused the US government to change the composition of the penny. The pennies we know today consist of a copper coating, which contains mostly zinc metal, and has a 2.5% mass.
The contents of the metal substance require the metals in a sample be dissolved. From past experiments we learned that Zn will dissolve in acidic solution as 〖Zn〗^(2+), however, Cu will …show more content…
This was due to the fact that before this time, the penny consisted of mainly copper and a little zinc and tin. So the government placed a mandate that all pennies must have a copper mass of 2.5%. This experiment was conducted to determine if the government mandate of mass percent of copper in the penny was 2.5%. The penny was placed in a solution to drive off most the zinc so copper is the only element left. After most was driven off, the solution was placed in a spectrometer to see how much light the copper absorbed. The %Cu was calculated and a T-test and Q-test was conducted. The Q-test was conducted at a 95% confidence level (0.97) and the results concluded that there were no outliers. After conducting the t-test at a 95% confidence level (2.78), it has been determined that the hypothesis is accepted. The mass percent of each of the three pennies were at or below the 2.5% mandated by the government.
Although the hypothesis was accepted, there are still possibilities of errors while conducting this experiment. Rounding off the digits of the calculations and not using the appropriate amount of sig figs could have thrown the data off. The other limitations to look at is the possible limitation of the actual equipment. While conducting the experiment, the measurements could have been off or the containers the solutions were put in could have not been dried completely. The excess of water might have caused an error in the data
The main objective in this experiment is to determine if the claims made by the US government, regarding the spectrophotometric analysis of a copper penny hold true. Before 1982, the Lincoln cent contained 95% copper and 5% various mixtures of zinc and tin. As the cost of copper increased, the cost to produce the penny was more than the actual face value of the penny. This caused the US government to change the composition of the penny. The pennies we know today consist of a copper coating, which contains mostly zinc metal, and has a 2.5% mass.
The contents of the metal substance require the metals in a sample be dissolved. From past experiments we learned that Zn will dissolve in acidic solution as 〖Zn〗^(2+), however, Cu will …show more content…
This was due to the fact that before this time, the penny consisted of mainly copper and a little zinc and tin. So the government placed a mandate that all pennies must have a copper mass of 2.5%. This experiment was conducted to determine if the government mandate of mass percent of copper in the penny was 2.5%. The penny was placed in a solution to drive off most the zinc so copper is the only element left. After most was driven off, the solution was placed in a spectrometer to see how much light the copper absorbed. The %Cu was calculated and a T-test and Q-test was conducted. The Q-test was conducted at a 95% confidence level (0.97) and the results concluded that there were no outliers. After conducting the t-test at a 95% confidence level (2.78), it has been determined that the hypothesis is accepted. The mass percent of each of the three pennies were at or below the 2.5% mandated by the government.
Although the hypothesis was accepted, there are still possibilities of errors while conducting this experiment. Rounding off the digits of the calculations and not using the appropriate amount of sig figs could have thrown the data off. The other limitations to look at is the possible limitation of the actual equipment. While conducting the experiment, the measurements could have been off or the containers the solutions were put in could have not been dried completely. The excess of water might have caused an error in the data