Grignard Synthesis of Benzoic Acid

Aligned to Classic Chemistry Advanced Placement Laboratory
Once the Grignard reagent is prepared, it can be used to prepare the target compound. In this experiment the target compound is a carboxylic acid. To prepare a carboxylic acid, the Grignard reagent is carboxylated in a reaction with dry ice. After the reaction is complete, hot water is added to evaporate any remaining solvent. Acid is added to dissolve the magnesium salts and liberate the carboxylic acid. Once the solution is cooled, the acid can be collected. In this experiment, we will prepare a carboxylic acid (benzoic acid) by the Grignard method.

Kit Includes:
1 x 5 g Magnesium Metal Turnings
2 x 25 ml Tetrahydrofuran
1 x 20 ml Bromobenzene
1 x 25 ml Hydrochloric Acid, 36%
1 x 10 g Decolorizing Carbon