Hi,
My lab recently ran out of sodium benzoate, so my lab mates and I were trying to figure out how to make sodium benzoate from its precursors (sodium hydroxide and benzoic acid). Does anyone know a recipe that yields a pure product (>95%)? We tried to dissolve a stoichiometric mixture by first dissolving a set number of moles of NaOH, then we began to add benzoic acid to result, the benzoic acid didn't dissolve well at room temperature so we heat the mixture to boiling. At boiling the mixture fully dissolved. We then let the mixture cool and solid crashed out half-way through the cooling process. I suspect what crashed out was benzoic acid, since sodium benzoate should have remained in solution given the liquid volume. Thanks in advance for any tips! Any help is greatly appreciated.