In a typical reaction, 5 mmol of the benzaldehyde and 5 mmol of the acetophenone (all commercially available) were added to a 3-inch porcelain mortar, 200 mg of solid NaOH (about a pellet) was added and the mixture ground with a pestle for about 5-10 minutes. In most cases, after a few seconds of grinding, the reaction mixture turned yellow and became pasty. Grinding was continued until the mixture solidified and the solid broke up in small particles. All mixtures solidified upon grinding. In all cases, 10 mL of distilled water was added at the end of the grinding period and the product mixed well with the water, with the pestle and a spatula used to dislodge the solid from the mortar's wall. The suspension was vacuum filtered using a Buchner funnel. Mortar and pestle were rinsed with 5 mL of water and the rinses collected on the same filter. The product was washed on the filter with an additional 5-mL aliquot of water and it was allowed to air-dry on the filter. It was then weighed and analyzed by melting point and NMR spectroscopy (solutions were made in CDCl3 and the spectra obtained using a 500-MHz instrument). The crude products were recrystallized from 95% ethanol-water, and the melting points of the purified products were determined.
Data & Calculations: assume you have obtained 0.88 g of crude product, and 0.62 g of dried, crystalline product. What melting point would you expect for the product? How might the melting point change before and after the crystallization step?