I posted this yesterday, I was wondering if anyone could still help me...

When doing an acid-base extraction, there are certain rules when chosing the solvent that is to be used in extraction.. one being that it should have a low boiling point. I understand this to be so that the solvent (in this case, ethyl) can be removed rapidly from the compound after extraction without problems.

Can someone further explain why the solvent needs to have a low boiling point? Like, why can't you use dimethylformamide which has a higher boiling point?

Any help would be appreciated. Thanks.

The higher the bp (higher vp), the more compound will vaporize, as it has a vp also.

Hence go for the largest difference in bp that you can get. An added advantage of using a low boiling solvent is that it is more easily removed from the product.

DMF is not good as an extracting solvent as it is miscible with water!

Certainly! In acid-base extraction, one of the key steps is to selectively extract a desired compound from a mixture using a solvent. The choice of solvent is important because it determines how efficiently the extraction process will occur.

The reason for using a solvent with a low boiling point is to facilitate the subsequent separation of the compound from the solvent. After extraction, the solvent needs to be removed from the compound to obtain a purified product. If the solvent has a high boiling point, it would take a longer time and higher temperature to evaporate, which can be impractical and may lead to decomposition or other unwanted reactions of the compound.

For example, if a solvent like dimethylformamide (DMF) with a boiling point of 153°C is used for extraction, it would require significant heating and longer evaporation times to remove it completely from the compound. This prolonged exposure to heat can increase the chances of thermal degradation or other side reactions, affecting the purity and yield of the final product.

On the other hand, using a solvent with a low boiling point, such as ethyl acetate (boiling point 77°C), allows for easier and rapid removal of the solvent. By applying mild heat or subjecting it to reduced pressure, the boiling point of the solvent can be easily reached, causing it to evaporate quickly while leaving behind the extracted compound.

Therefore, selecting a solvent with a low boiling point is crucial in order to ensure a more efficient and effective extraction process, minimizing potential degradation and maximizing overall yield and purity.