1/13/2024 0 Comments Liquid emulsion meaning![]() ![]() For simplicity’s sake, we will assume that the product is a neutral compound. The funnel is narrow at the nozzle, which is a structural feature that allows us to accurately separate the two phases. The funnel is equipped with a top and a nozzle, and the nozzle can be closed or opened with a stopcock. These come in many different sizes, but the typical size is 100 mL, which you will encounter in several labs at PSU. The typical apparatus used in an extraction, is the separatory funnel. ![]() Neutralizing the acidic phase will depro- tonate the basic compound, which may precipitate, or may require a second extraction with an organic solvent. We can protonate the basic compound by using an aqueous acid, pulling the protonated compound into the aqueous phase and discarding the organic phase. If the product is basic, we can perform a sequence very similar to the acidic compound above. Acidification of the aque- ous phase can precipitate the desired product. Because very few organic compounds are soluble in water, we can discard the organic phase which now contains any byprod- ucts and/or unreacted starting materials. This will pull the deprotonated compound into the aqueous phase. If the desired compound is acidic, we can selectively deprotonate that compound by using an aqueous base. is neither acidic nor basic), the extraction sequence usually involves simply extracting with an organic solvent several times. If the desired organic compound is neutral (i.e. We will first examine some typical scenarios involving extraction, then move on to discuss technical details to keep in mind. It depends on both the nature of the compound, but also the nature of the aqueous phase. It is important to note that the desired compound (usually an organic molecule) can in theory be in either phase. Liquid-liquid extraction (we will refer to it simply as extraction from now on) is typically conducted with one aqueous phase (either pure water, or an aqueous solution) and one organic phase. A very typical extraction flow diagram is shown below, where a reaction mixture is quenched with water, extracted (several times), washed with brine, dried, filtered and finally evaporated to yield a crude product or a pure product. Liquid-liquid extraction is also very commonly used for washing an organic phase, for example to remove inorganic compounds, or to protonate or deprotonate bases or acids, respectively, so they become soluble in the aqueous phase. Liquid-liquid extraction involves the exchange of certain com- pounds between two solvents that are immiscible or only partially miscible. ![]()
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