CHEM123 Study Guide - Final Guide: Acetic Anhydride, Potassium Dichromate, Diffraction Grating

• School: University of Waterloo
• Department: Chemistry
• Course: CHEM123
• Professor: Carey Bissonnette

Document Summary

Accuracy is how close you get to the actual mass, and precision is if you can get that accurate. Acetaminophen is formed when the amine group of p-acetaminophen is given an acetyl group from acetic anhydride to form an amide product is acetaminophen and by-product is acetic acid. The crude solid must be separated from the acetic acid through vacuum filtration then purified through recrystallization by heating it in a minimal amount of solvent. The hot solution must be cooled to room temperature and then put in an ice bath so that the crystals can solidify. These crystals are more pure than the crude solid because the impurities dissolved in the cold solution. To measure the melting point of the crude and pure solid, samples were taken from each and were placed into melting point tubes to be inserted into a meltemp melting point apparatus.