Both in everyday life and in the scientific field, mixtures that involve a solid element and another liquid are very common , usually the first acting as an element to be dissolved and the second as a space for dissolution. This distribution is merely proportional, and the majority substance acquires the name of solvent while the minority is called solute.
Sometimes the joining process is simple, while in others the use of specially constituted devices is demanded. In the food, cosmetic, pharmaceutical and chemical industries, the mixer is usually used, which recirculates the solids through a tank, being placed manually or automatically in a hopper. This is frequent for mixtures that would be very difficult to prepare manually. As in the other types of mixtures, solutions of solids in liquids can be presented in different ways according to the characteristics of these elements:
- Solutions :They will be solutions if the formation is produced by the breakdown of the solid to the molecular or ionic level. It is frequent that the solids that are part of the solutions react well in some solutes and badly in others.
- Suspensions : Suspensions are called to those that do not reach the state of dissolution because the particles of the solid can be seen with the naked eye or with a microscope: this gives the compound a cloudy appearance.
- Colloids : Colloids are called combinations whose particles can only be seen under the electron microscope, together they form a clear aspect that denotes the presence of a solid in combination with a liquid.
- Gels : Finally, the gels are the solid-liquid combinations that constitute an intermediate state, not formally fulfilling the characteristics of either of the two groups. In everyday life appear many of these, such as cheese, gelatin or some inks.
The mixtures between solids and liquids , like the other classes, also have different ways of being separated : science has been very involved in the pursuit of this objective, since it becomes fundamental for many purposes that it has. The processes by which this division is carried out are:
- Centrifugation : The same technique to eliminate water in dishwashers or clothes washers.
- Crystallization : The total elimination of the solvent, by means of a rapid vaporization , procedure used to obtain common salt.
- Chromatography : Substance drag by the action of a rising liquid, the filtration (step of the compound by a special paper that filters the solid).
- Sedimentation : Procedure to leave the mixture at rest, characteristic of the solutions in which the solid is suspended in the water.
Examples of Mixtures of solids and liquids
Cement (mix of water with sand)
Powder juicesMud (typical mixture of cloudy character)
Blood (colloidal mixture)
Yogurt (usually in a state similar to colloid)
Ink with alcohol
Mixture of washing powder and water
Egg white (suspension)
Saline solution (water and salt)
Dairy formulas ( proteins and water)