The Determination of Copper in Brass by Optical Spectroscopy, Lab Report Example

Abstract

Many individuals are concerned with the availability of copper on the market. Therefore, chemists are interested in determining whether optical spectroscopy can be used to determine the percentage of copper in an impure sample of brass. It is hypothesized that this method will allow chemists to reveal the copper/brass ratio using predetermined knowledge of the chemical properties of these metals. After examining this metal using spectroscopy, the ratio, percentage, confidence interval, % error, and % difference was calculated. The copper UV readings revealed that as the optical absorbance increased, the concentration of the metal increased as well. It was found that the average percentage of copper in the three samples that were tested came to 75.75% of the sample, with a standard deviation of 2.13% Furthermore, the confidence interval was +/- 5.30% and the % Cv was 2.81%. This is important because a majority of these samples were mostly copper, indicating that they are more valuable than typical copper/brass contaminants. It would be necessary to determine a manner to isolate these two elements in order to take full advantage of the knowledge of this identity.

Introduction

Over the past several years, the value of copper has risen above the value of brass, indicating the want of many scrappers to determine the ratio of copper and brass in the metal samples they have selected (Earthworks Recycling). Therefore, the purpose of this experiment is to determine whether the percentage of copper in brass can be examined using optical spectroscopy. It was hypothesized that the purity of the metal could be evaluated using this method, indicating that further computational analysis would allow for the determination of the ratio of copper in the impure brass. It is possible that these two metals can be purified once this knowledge is acquired.

Discussion

The results indicated that the average percentage of copper in the three samples that were tested came to 75.75% of the sample, with a standard deviation of 2.13%. In summary, the confidence interval was +/- 5.30% and the % Cv was 2.81%. This indicates that there is a higher percentage of copper, on average, in the samples compared to the percentage of copper in the same samples. This evidence can be used to the advantage of scientists, as future experiments could focus on extracting the copper from the brass sample in a pure manner. The difference in melting points of these two metals could be used for this experimental design, although it would be necessary to obtain machinery that is capable of reaching these very high temperatures.

An additional experiment can be performed to confirm these experimental findings. Although optical spectroscopy was utilized in this case, it would may be reasonable to adopt the mass spectrometry assay to the quantification of metals. Furthermore, if the isolation concept is performed, it would also be reasonable to measure the weight of the resulting brass and copper extracts and to compare the new weights of these samples to the total weight of the impure sample to determine the % by mass of each extract.

Lastly, it may be ideal to perform this experiment again using a greater number of samples. Although the results obtained had a small computed confidence interval, it would be possible to reduce this number even further using more samples, allowing us to be even more certain of our calculated results.

Works Cited

Earth Works Recycling. N.D. Web. 19 October 2014. <http://www.earthworksrecycling.com/prices/>