How Do You Determine Benzoic Acid Melting Point?
Melting point analysis provides easy identification of solid substances, such as benzoic acid, in the lab. Using a melting point device such as a Mel-Temp, students can observe the sharp melting points of pure substances and the different melting ranges that appear in impure substances. Make sure the melting point device is close to room temperature before beginning a melting point analysis. Using a spot plate and the butt end of a test tube or a mortar and pestle, grind the sample of benzoic acid into a fine powder. Pack it into a glass capillary tube so that the level of powder is about 2 mm high, as recommended by Boston College. Turn the capillary so that the closed end is down. Pack it tightly by dropping it through a long tube over the lab bench or tapping it on the bench directly. This prevents uneven heating, which can interfere with accuracy. Set the melting point device to a temperature that will create relatively slow heating. Mel-Temp devices have a setting that reaches max
