Solvents , also known under the name of “solvents”, are substances that allow the dispersion of another in it, always at the molecular or ionic level, so that, in this way, the solution is made, dissolving the solute , and it is found in a higher proportion.
The interaction of solvent molecules with those of the solute is known as “solvation”.
Classification of solvents
The solvents can be classified according to their polarity :
1. Polar solvents : these are substances in which the distribution of the electronic cloud is characterized by its asymmetry and contains molecules with both positive and negative pole, distanced and maintaining electrostatic interactions between the dipoles. This is observed for example in water, which is the universal solvent. These solvents can be subdivided into:
- Protic solvents : having an OH or NH bond, such as water (HOH), ethanol (CH 3 -CH 2 -OH) and acetic acid [CH 3 -C (= O) OH].
- Aprotic solvents : they do not have OH or NH bonds, so they do not give or receive electrons, such as acetone (CH 3 -C (= O) -CH 3 ) and THF or tetrahydrofuran.
2. Non-polar solvents : these are usually organic substances, in which the distribution of the electronic cloud is not asymmetric , as in the previous case, but symmetric. This results in a lack of polarity, which is why they talk about permanent dipole substances.
Within the geometric configuration of the molecule are the polar bonds . They dissolve the apolar substances by interactions between induced dipoles. Compounds such as diethyl ether, toluene, ketones or cyclohexane are clear examples of apolar solvents.
The chloroform has a particular quality, put the three chlorines produce negative charge that carbon is positively charged, while the hydrogen is partial negative charge. That is why it has a certain polarity.
According to its chemical nature , the following solvents are identified:
Organic solvents: these are those volatile organic compounds that are used individually or in a mixture with other compounds, without this generating any modification, to dissolve elements such as raw materials, products or waste, to clean, among other things.
They are classified according to their chemical composition:
Hydrocarbons: carbon is the basic elemental core of this solvent , as well as hydrogen (CH 4 ) . Both can be saturated or not, thus forming open or closed chains that have derivatives.
In this way, a hydrogen is replaced by a specific functional group or, by atoms of halogen elements, such as, among other examples, fluorine or iodine. Within this type we can find:
-The simple ones:
- Open chain saturated
- Saturated cyclics
- Unsaturated cyclics
-The derivatives : these replace some hydrogen particle by a certain functional group, which may be the following:
No hydrocarbons : in this case, its basic element is not carbon hydride, but carbon disulfide (CS2)
You can also differentiate the solvents between:
Organic : these are the solvents that are only made up of a single chemical compound
- Simple: these, however, may have certain impurities from another compound that is in a non-pure solvent.
- Compounds or mixtures : in this case they have mixtures of different solvents in an intentional way, which depends on the use that will be given to them