Crystallization

We explain what crystallization is and what this chemical process consists of. In addition, the methods used and examples of crystallization.

1. What is crystallization?

It is known as a crystallization process to a chemical process in which a gas is transformed, a liquid or a solution, in a set of solid crystals Crystals consist in an ordered set of molecular bonds so that the crystallization can be used to separate the ingredients from a homogeneous mixture.

The crystallization can be carried out through various methods, which can lead to the selective alteration of the physical conditions of Temperature or pressure, as well as the addition of certain chemical substances. The form, thema and depend on the conditions punctual in which the process occurs of the time during which it is allowed to occur.

The crystals obtained by this method are solid formations, endowed with a well defined pattern of diffraction, depending on the element and of the conditions in which the crystallization occurs, these will have one form or another, and may have color, transparency and other chemical properties .

Crystals are common in the `` mineral '' nature and are classified according to their properties in: crystals s s solid, crystals luminous, crystals nicos,
Covalent crystals, molecular crystals and crystals.

See also: Inorganic Compound.

1. Crystallization Examples

• F ormation of frost . Under certain conditions of ambient humidity, water vapor from the air can crystallize directly on cold surfaces such as glass or metals, and form snow-like structures, called frost . Some freezers tend to form it too. These are water crystals, whose constitution is very regular and very well formed.
• Water freezing Ice is frozen water, and as such it is not a crystal. But during the early freezing phases of this liquid, you can see how dendrites and other submerged crystalline structures arise.
• Evaporation of seawater . To obtain salt crystals, as well as desalinated water, water taken from the sea is usually boiled. In this way, the liquid becomes a gas (water vapor) leaving the dissolved salts in the container. These, reuniting their molecules, take the form of perfect saline crystals.
• Silver crystals for photography . Silver crystals are useful for certain artifacts of the film industry or of old photography (not digital, obviously), since being sensitive to light, these crystals are rearranged against light, thus copying the light impression. To obtain them, compounds such as bromide, chloride or silver iodide are used.
• Calcium oxalate crystals . Formed by the accumulation of salts and calcium in the kidneys, these crystals are usually painful and sometimes require even surgical intervention, as they hinder the normal expulsion of urine. They have the shape of small dark stones, known as kidney stones, or "stone" or "sand" in the kidneys.