Chemistry studies substances and their properties. When they are mixed, mixtures arise that acquire new valuable qualities.
What is a mixture?
A mixture is a combination of individual substances. Their manufacture is not only done by scientists in laboratories under certain conditions. Every day we start with aromatic tea or coffee, in which we add sugar. Or cook a delicious soup, which must be salt. These are the real mixes. Only we do not think about it at all.
If it is impossible to distinguish particles of substances with the naked eye, this is a homogeneous mixture (homogeneous). They can be obtained by dissolving the same sugar in tea or coffee.
But if sand is added to sugar, their particles can be distinguished without difficulty. Such a mixture is considered heterogeneous or heterogeneous.
Inhomogeneous mixtures
In the manufacture of mixtures of this kind, you can use substances that are in a different state of aggregation: solid or liquid. A mixture of ground pepper of various kinds or other seasonings are most often heterogeneous dry formulations.
If any liquid is used in the preparation of a heterogeneous product, then the resulting mass is called a suspension. Moreover, there are several types of them. When liquids are mixed with solids , suspensions form. Their example is a mixture of water with sand or clay. When the builder makes cement, the cook mixes the flour with water, the child brushes his teeth with paste - they all use suspensions.
Another variety of heterogeneous mixtures can be obtained by mixing two liquids. Naturally, if their particles are distinguishable. Put vegetable oil in water - and get an emulsion.
Homogeneous mixes
The most famous of this group of substances is air. Each student knows that it contains a number of gases: nitrogen, oxygen, carbon dioxide, water vapor and impurities. Can they be seen and distinguished with the naked eye. Of course not.
Thus, both air and sweet water are homogeneous mixtures. They can be in different aggregate states. But most often liquid homogeneous mixtures are used. They consist of their solvent and solute. And the first component is either liquid or taken in a larger volume.
Substances cannot dissolve in infinite quantities. For example, in a liter of water you can add only two kilograms of sugar. Further this process simply will not occur. Such a solution will become saturated.
An interesting phenomenon is solid homogeneous mixtures. So, hydrogen is easily distributed in various metals. The intensity of the dissolution process depends on many factors. It increases with increasing temperature of the liquid and air, when grinding substances and as a result of their mixing.
Surprising is the fact that in nature there are no absolutely insoluble substances. Even silver ions are distributed between water molecules, forming a homogeneous mixture. Such solutions are widely used in everyday life and human life. For example, everyoneβs favorite and healthy milk is a homogeneous mixture.
Methods for the separation of mixtures
Sometimes it becomes necessary not only to obtain homogeneous solutions, but also to separate homogeneous mixtures. Suppose there is only salt water in the house, but you need to get its crystals separately. For this, a similar mass is evaporated. Homogeneous mixtures, examples of which were given above, are most often separated in this way.
Based on differences in boiling point, distillation is based. Everyone knows that water begins to evaporate at 100 degrees Celsius, and ethyl alcohol at 78. A mixture of these liquids is heated. First, alcohol vapor evaporates. They are condensed, that is, transferred to a liquid state, in contact with any cooled surface.
By means of a magnet, mixtures of metals are separated. For example, iron and wood filings. Vegetable oil and water can separately be obtained by sedimentation.
Heterogeneous and homogeneous mixtures, examples of which are illustrated in the article, are of great economic importance. Minerals, air, groundwater, seas, food, building materials, drinks, pastes - all this is a combination of individual substances, without which life would be simply impossible.