Isolation Of Naphthalene Lab Report

In this experiment, the goal was to isolate an organic substance. Using extraction, a basic, acidic, and neutral substance was expected to be extracted from the original unknown compound.
Extraction is a process that allows the separation of substances that were previously mixed together through the use of a solvent1. This can be useful in situations where the substance has both the desired product and undesired byproducts in it. In order for extraction to work, the solvent must be able to target only one part of the substance. The solvent used is always immiscible so that it forms two separate layers2.
Extraction is performed with the use of a separatory funnel. This funnel is designed to have one open side and one side that
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During the process of separating the layers in the separatory funnel, it is possible that some of the organic layer could have accidentally been drawn off. The naphthalene was also transferred between containers several times, although there were steps in the procedure to ensure that would have little effect (such as rinses with ethanol). The wooden stick that was used during the steam bath could have had some of the product on it which would have been removed with the stick.
It is less clear why the benzoic acid was overproduced. Some of the organic layer may have been drawn off with it, but the vacuum filtration should have left only the benzoic acid. There could have been an error in weighing the filter paper before the procedure. There also could have been contaminants in the basic extract, causing more than just the benzoic acid to be filtrated. There is also the chance that too much starting material was added.
Overall, the melting points were pretty close. It appears as though all three compounds were successfully extracted. Both the melting points of naphthalene and meta-nitroaniline seem to match almost exactly with the melting point according to literature. However, there is some concern for the melting point of the benzoic acid extracted. The found melting range seems to be several degrees larger than the known melting
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It is more likely however that the substance was simply heated too quickly when tested, and therefore did not have enough time to fully melt.

Overall, it seems as though the extraction of the basic, acidic, and neutral substances from the original unknown compound was a success. Once extracted, each was able to be identified as benzoic acid, meta-nitroaniline, and naphthalene. The melting points of the extracted compounds matched the melting points of the same known compounds fairly closely, indicating further that this is what was extracted.


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