The colored layer that appears on metal surfaces due to oxidation is called oxide.
Oxide , a term that comes from a Greek word meaning "acid" , is the chemical compound that arises with the combination of oxygen and a metal or a metalloid . The layer of different colors that forms on the surface of metals due to oxidation is also known as oxide.
Oxides can be found in solid, liquid or gaseous state at room temperature. Those oxides that have a single oxygen atom are called monoxides . If they have more than one oxygen atom, they begin to be named according to the Greek numerical prefixes: with two oxygen atoms, dioxides ; with three oxygen atoms, trioxides ; and so on.
Types of oxides
The oxidation state is the number of electrons that an atom acquires or gives up in a chemical reaction to achieve a certain stability. Periodixes are substances with an oxygen-oxygen bond in the -1 oxidation state. Superoxides , on the other hand, are binary compounds.
Another classification of oxides is linked to chemical behavior. Basic oxides are formed by the combination of a metal and oxygen. When water is added, they form basic hydroxides. Acid oxides are derived from a nonmetal and oxygen. With water, they form oxacids. Amphoteric oxides , finally, have the participation of an amphoteric element (oxides capable of acting as acids or bases depending on the reaction).
According to the stoichiometry of the compound , we can speak of binary oxides (the combination of oxygen and another element) or mixed oxides (formed by oxygen and two other different elements).
The appearance of rust is common in humid environments.
NO, resource or weapon of destruction?
Also called nitrogen monoxide and nitric oxide, nitrogen oxide (NO) is a colorless gas with low solubility in water that is found in mammals in discrete quantities. Likewise, due to the pollution produced by cars and power plants, NO is found in the air we breathe and shows great instability: when it comes into contact with oxygen, it oxidizes in a short time and becomes carbon dioxide. nitrogen.
In the 1970s, it was discovered that nitrates used to treat chest pain and some cardiovascular disorders release this gas, which helps dilate blood vessels and relaxes the tissues in their walls. internal.
Almost twenty years later, it was observed that our body is capable of generating small amounts of nitrogen oxide from the amino acid arginine. This was essential to understand the functioning of several organic nitrates that were used as medications to treat angina pectoris (a chest condition), which also release NO.
Production and use of nitrogen oxide
This gas can be produced from a wide variety of cell types, such as nervous, epithelial, and inflammatory cells. In addition, it is worth mentioning that NO can act as a neutraltransmitter when it is in our brain, since it easily crosses cell membranes thanks to its affinity for organic molecules composed of hydrogen and carbon.
Given its numerous benefits in the treatment of disorders of the human body, it is not difficult to understand why medicine has found various applications for nitrogen oxide. On the other hand, it can also be used to preserve food. As an interesting fact, it is known that some microorganisms use NO to eliminate cells.
Human action has considerably increased the percentage of NO present in the atmosphere . This carries the risk of acid rain , once NO is converted to nitric acid . On the other hand, this gas is one of the causes of the hole in the ozone layer and contributes to the warming of the planet.