CHEM 233 Lecture Notes - Lecture 6: Dichloromethane, Fourier-Transform Infrared Spectroscopy, Separatory Funnel
Document Summary
Base extraction of benzoic acid from acetanilide recrystallization of products. The purpose of this lab is to explore methods of separation, liquid-liquid base extraction, and recrystallization in order to analyze two substances within an initial mixture. The mixture to be separated is a 1:1 binary mixture of benzoic acid and acetanilide. In order to separate the two compounds, the mixture is treated with sodium hydroxide and methylene chloride, leaving two distinct liquid layers to be extracted. By separating the layers, heating them and cooling them, solids in the form of crude heated products, or ice-cooled precipitates can be extracted and purified through recrystallization. The liquid-liquid separation method works by using the difference in solubility of the two compounds being extracted. These solubilities can be connected to the polarity of the molecules like. Attracts like (or in this case like dissolves like). Immiscibility is another key point to the separation.
