Our Experiment to Separate a Mixture of Organic Compounds Essay

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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 …show more content…

Initially, the organic carboxylic acid becomes a charged species after it is deprotonated by a base like sodium hydroxide, producing a carboxylic salt. After completing the extraction, an acid, such as hydrochloric acid, is added to the basic aqueous solution causing the sodium carboxylate salt to change back to the default carboxylic acid, which will precipitate out of solution since it is water insoluble. Recrystallization is a technique when a solute is dissolved in a hot solvent (destruction of the impure crystal lattice) and is then precipitated out of solution as the solvent is immediately cooled (selectively producing a purer lattice). The unknown acid was recrystallized using hot water followed by hot ethanol in order to dissolve the solid, followed by cooling which resulted in the precipitation of the desired product. Afterward, melting point experimentation was used to match the melting point data of the unknown acid with the provided standards of the known acids. If there is a melting point depression, one has acted as an impurity to the other compound. In contrast, if there is no noticeable decrease in melting point relative to the two separate compounds; it is safe to say that they are the same substance.


What was the unknown identity of the acid after conducting melting point

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