Jessica Savarese Experiment 2: Recrystallization and Melting Point Purpose: Recrystallizing impure benzoic acid to separate the desired solid from the contaminating impurities. Procedure: Recrystallization - Use a hot plate to dissolve approximately 1.0 g of impure benzoic acid in 30-35 mL of hot water (at or near b.p.) in a 125 mL Erlenmeyer flask. Use glass stir rod to crush large chunks of crystal to help dissolve. If there is small amount of material not dissolved after small addition of solvent (water), do not add more solvent; use MINIMUM amount of solvent. If there is any insoluble solid residue, gravity filter this hot solution through a fluted filter paper and a stemless funnel. Preheat funnel by running a SMALL AMOUNT of hot solvent (water) through the funnel to reduce loss of recrystallization. To further reduce the amount of loss of material, don’t fill the funnel with solution, rather add small portions of the hot solution so a minimum amount of solution is in the funnel at once.