Our Experiment to Separate a Mixture of Organic Compounds

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Purpose/Introduction What were we trying to accomplish with this experiment? What method did we implement to accomplish the task? What techniques were used to purify and identify the product(s) of the reaction? In this experiment, an acid-base extraction was done to separate a mixture of an unknown acid and fluorene, a neutral compound. The possible unknown acids were 2-chlorobenzoic acid, 3-chlorobenzoic acid, and 3-methylbenzoic acid. The purification of the isolated unknown acid was performed by recrystallization and its identity was established by analyzing the melting point range of the pure product and comparing it to the provided standards. In addition, a mixed melting point experimentation enhanced the fidelity of the unknown's identity when approximately equal amounts of the unknown and one of the standards (at a time) were mixed and the melting point range was recorded. Theory: Explain the theory behind acid base extraction. Why is it possible to separate compounds of different polarity? What establishes the selection of solvents used in an extraction? Briefly comment on how you will recrystallize the unknown acid and how melting point analysis is necessary. A convenient method of separating a mixture of organic compounds is recognized as liquid-liquid extraction, which involves the dispersion of a substance between two immiscible solvents using preferential solubility. Strategically using the differences in solubility of the interested solute, the compound can be transferred from one liquid part to the other during extraction. Organic acids and bases can be separated from each other by using an organic solvent like diethyl ether and a polar solvent such as water. Diethyl ether is an appropriate solvent since it wil... ... middle of paper ... .... Conclusions and Future Experiments: How would you summarize your results and analysis? What questions remain unanswered? What questions were raised by your results and analysis? In summary, acid base extraction is a useful technique when attempting to transfer an organic compound from an organic solvent (ether) to an aqueous solvent after deprotonation with an appropriate base (NaOH). After transferring the unknown acid to the aqueous layer, precipitating it out of solution with a strong acid (HCl--protonation), followed by recrystallization, the unknown acid was able to be identified as 2-chlorobenzoic acid based off of melting point experimentation. A question that remains unanswered may be how many extractions are needed in order to have a plateau for maximum recovery? This is essential in order to have desirable results when testing for identity purposes.

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