Green Soap: An Extraction and Saponification of Avocado Oil

An introductory level green chemistry experiment is described that places a new twist on soap-making in lab. In this experiment, oil is extracted from an avocado, after which the oil is saponified to produce bars of green craft soap. Commonly used extraction solvents, such as petroleum ether, methylene chloride, and hexane, are replaced with safer ethyl acetate to extract the oil. Students find the experiment helpful in discovering the reality of fats and oils in foods, and in becoming aware of the direct relationship between oils in plants and soap. This experiment has been successfully carried out by students of introductory organic chemistry lab classes, but could be used by a general chemistry or an advanced placement high school class.