![]() The mineral base will remove the proton, leaving the original organic compound. ![]() That can be done by adding a mineral base, such as sodium hydroxide. If we want the original compound in a pure form, we need to take that proton away. However, the basic compound is stuck in the water, and it isn't the same compound anymore. Evaporation of the ether gives the pure, neutral compound. Now the neutral compound is alone in the ether. The water sticks to these solids, which are then filtered off. Water removal is most easily done by adding a drying agent, such as magnesium sulfate or sodium sulfate. Once the ether has been evaporated, there would be some neutral compound, but it would be mixed with water. This step is necessary because ether tends to dissolve a lot of water in it. What's the difference between evaporating and drying? Have you ever been to the beach or taken a shower? Drying refers to the removal of water. However, as a practical matter, the ether would have to be dried first. ![]() The neutral compound could be isolated simply by evaporating the ether. Some organic solvents do have a higher density than water, so the aqueous solution would float to the top in those case.Īs a result, the ethereal solution would contain only the neutral compound, not the basic one. The water is on the bottom in this case because water has a higher density than ether, so it will sink to the bottom (along with anything dissolved in it). Note that in the drawing, the ether is represented in yellow, whereas the water is shown in blue. The basic compound would become ionic, and more water-soluble. The proton would be transferred to a basic compound, but not to a neutral one. Suppose an aqueous solution of mineral acid, such as HCl, were shaken vigorously with an ethereal solution of an organic base and an organic neutral. In this case, a proton might be added via reaction with a strong mineral acid (represented by HX in the drawing). There is also a basic one, which reacts with acids by picking up a proton. There is a neutral one which doesn't react with any acids or bases. Suppose you have a mixture of two compounds. These compounds can easily be made into ions either by adding a proton (an H ion), making the compound into a positive ion, or by removing a proton, making the compound into a negative ion. However, if the organic compound is rendered ionic, it becomes more soluble in water than in the organic solvent. The method rests on the assumption that most organic compounds are more soluble in organic solvents than they are in water. The organic solvent may be any carbon-based liqiuid that does not dissolve very well in water common ones are ether, ethyl acetate, or dichloromethane.Īcid-base extraction is typically used to separate organic compounds from each other based on their acid-base properties. It typically involves different solubility levels in water and an organic solvent. \)Īn acid-base extraction is a type of liquid-liquid extraction.
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