Question

Purpose: Apply the techniques learned in CHM237 course to isolate, purify, characterize and identify the different chemicals in a mixture of 1:1 Benzophenone/2-iodobenzoic acid. Only do for mixture A.

I just want a procedure that will allow the separation of a 150 mg Benzophenone/2-iodobenzoic acid mixture. Using one or more of the following solvents: Hexane, Dichloromethane (methylene chloride or DCM), Diethyl ether, Methanol, anhydrous sodium sulfate, Ethanol, HCl 6M solution, & NaOH 3M solution.

After the mixture assignment, you must work with your lab partners to figure out a procedure to separate, purify and characterize your mixture. You will need to write the compound information and flowchart in YOUR LAB NOTEBOOK (individually). It is encouraged to bring the procedure to the Substitution section to get help and direction from the TA. In order to help you to come up with a procedure, there will be a recitation video about the information you need to look for and how to design an experiment. During the Experimental Final week, you need to use their flowchart/procedure to isolate, purify and characterize your two compounds.

Answer 1

Drawn below is the flochart for the separation of benzophenone and 2-iodobenzoic acid. First step is addition of diethylether solvent and then 3 M NaOH. Base deprotonates benzoic acid proton and forms salt which goes in water. Separate the layer and add 3M HCl to aqueous layer to reprecipitate benzoic acid. The organic phase separated was dried over Na2SO4 and solvent removal on rotary evaporator (rotavap) gives the pure product.

After the pure compounds are obtained, melting point of both the compounds are taken and are compared with the literature melting points for the purity check.