Why is an extraction a useful method of "pre-purification" of organic compounds? what physical properties does the process rely on?

Explanation :

Extraction : It is a separation technique in which one compound is separated from a mixture of compounds.

In  a chemical process, the solution may not contain only the desired product but there maybe a mixture of products present.

So, for obtaining the desired product we need to get rid of the other products in a mixture like catalyst (if used), other by products or unreacted starting material.

For a compound to be extracted it has to be soluble in the extracting solvent.

Therefore, this process is based on the miscibility of solute and solvent in a mixture.

Extraction is a useful method of “pre-purification” of organic compounds in order to remove impurities. It is based on different solubilities of components in the mixture.

Further Explanation:

Purification of organic compounds:

The method of purification depends on the nature of substances and the type of impurities present in them. There are several methods for purification of compounds as follows:

1. Chromatography

2. Steam distillation

3. Fractional distillation

4. Simple distillation

5. Simple crystallization

6. Fractional crystallization

7. Sublimation

8. Azeotropic distillation

Extraction is the process to separate the desired substance mixed with some impurities. The mixture is added with a solvent such that the desired substance is soluble in it whereas the impurities are insoluble in it. Any substance is never so pure that it is free from impurities. So the undesirable substances are to necessary to be removed from the mixture and therefore extraction is an essential procedure in order to remove impure substances from the mixtures.

Extraction makes use of two different phases that are immiscible with each other. It is carried out on the basis of relative solubilities of different substances present in the mixture.

Learn more:

1. The reason for the acidity of water

2. Reason for the acidic and basic nature of amino acid.

Answer details:

Grade: College

Subject: Chemistry

Chapter: Solvent extraction

Keywords: extraction, purification, organic compounds, sublimation, crystallization, distillation, mixtures, impurities, chromatography, different phases, undesirable substances.