It is called a mixture to the various substances that are composed of two or more components, which are combined with each other, forming various substances and materials, whose components can be separated by physical processes, since their components are not chemically combined, conserving each element or compound its particular chemical characteristics, (although it is emphasized that certain mixtures do have chemical combinations under certain specific conditions), but usually there are no chemical interactions between the mixed substances.
Types of mixes
Basic Types of Mixes
Homogeneous mixtures.- Are those in which the elements and substances that make up the mixture form an equal grouping, that is, they have a uniform composition and cannot be distinguished with the naked eye.
Heterogeneous mixtures.- They are those in which the parts that compose them can be differentiated with the naked eye, whether the elements or the phases can be seen.
Main types of mixtures
Solutions.- Solutions are homogeneous mixtures made up of two or more elements or substances, in them the dissolved substances are called solutes and usually the solute is dissolved in the solvent in a minimal proportion compared to the amount of solvent, in them the chemical composition is variable. They are characterized by the fact that the chemical properties of the elements or substances that make up the mixture in solution do not change, that is, the chemical properties of each component is not altered, however the physical properties of the solution differ from those of the pure solvent, For example, the addition of a solute to a solvent causes the mixture to change its boiling point and freezing point, modifying the physical properties of the newly mixed compound.
The solutions can be of the following forms:
From a gas into a gas, from a gas into a solid, from a gas into a liquid, from a liquid into a liquid, from a solid into a liquid, from a liquid into a gas, from a solid into a gas, from a liquid into a solid, and from a solid into a solid. An example of a solution of a gas in a liquid that we can find is ammonia where ammonia gas dissolves in water creating water-ammonium.
Colloids.- Colloid mixtures, colloidal systems, or colloidal suspensions, are mixtures in which the solute is made up of very small particles (between about 10 nanometers and 1000 micrometers), particles that are “suspended” in the solvent (generally a liquid), in which they are dissolved. Colloids are mixtures that tend to form clots. Some examples are gelatin, as well as blood and milk, which are colloidal mixtures.
Emulsion.-Emulsions are homogeneous and stable mixtures of two liquids that usually do not mix easily, that is, they are not miscible, since they form two “bases” separated from each other since in most emulsions one of the liquids that make up the mixture is polar, while the other is non-polar, this is the case of water (polar) and oil (non-polar), which affects to the detriment of the union of the mixed substances, which is why they are usually added to this type of mixtures some type of emulsifier, which acts by reducing the surface tension forces in the boundary layer between the two substances when they are mixed (agitated), as in the case of oil and water, forming microscopic bubbles that allow them to “mix” immiscible substances. This is the case of mixture emulsions such as mayonnaise, where the emulsifier is the lecithin contained in the egg yolk, which allows the emulsion of water and fats (oil) to be carried out. Several emulsions belong to the group of colloid mixtures, in the case of milk, which is a mixture (emulsion) of various components, including substances such as water, calcium and fats, among others.
Suspensions.- Suspensions are heterogeneous mixtures, which are made up of tiny, non-soluble solid particles that are dispersed in a liquid medium (this is what is called the dispersing phase).
Another way to classify the various types of mixtures is through the physical method with which the substances that compose it can be separated.
Some types of mixtures according to the type of process that is carried out for their separation.
Types of mixtures by magnetic separation.- They are mixtures in which some of its components have magnetic properties, and this property is used for the extraction of these materials, leaving only the materials that are not magnetic. An example is mineral mixtures in which iron powder is found.
Separable Mixtures by Decantation.- This method is used in liquid mixtures where their components have different densities or weights, and where the mixed elements are not soluble in each other. It is the method used to separate some simple mixtures such as those that have some solid component suspended in a liquid, where a material is denser or heavier than the rest of the liquid, the liquid or less dense material being decanted to another container. In laboratories and industries, a special funnel is usually used to decant some mixtures (separation funnel), which contains a key with which the passage of the decanted substances is regulated.
Mixtures that are separated by Filtration.- This method is used in mixtures of solids and non-soluble liquids, a filter is interposed where the solid cannot pass, leaving only the liquid to pass through the tiny porosities of the filter.
Mixtures separable by Distillation.- Distillation is a method used to separate the components of a mixture of soluble liquids from each other, since the liquids that make up a mixture usually reach their boiling point at different temperatures. This method is used to vaporize one of the dissolved liquid substances, which are passed through a tube that is cooled so that the vapor condenses again and, already in a liquid state, is guided to another container, thus separating the liquids from the mixture. This method takes advantage of the various boiling points of liquid substances. An example of mixtures that are separated with this method is that of pure alcohol, which is separated from the corresponding mixture (liquor or wine) to which they belonged.
Mixtures separated by Screening.- This can be used for the separation of solid mixtures, composed of grains of various sizes. What is done is to pass the mixture through several sieves.
Mixtures that can be separated by crystallization.- In the mixtures that can be separated by this method, the mixture is heated, which causes the solvent to boil and evaporate, which causes the solute to conglomerate and dry, forming crystals as it solidifies. An example of this type of mixture is salt water, where the salt, when evaporated, forms crystals.