The concept of reducing agent It is used in the field of chemistry , within the framework of oxidation reduction reactions (also known as redox reactions ). In these reactions, the reducing agent releases electrons that are accepted by the oxidizing agent . Said transfer implies a change in the oxidation state.
It can be said that these reduction-oxidation reactions lead to two half-reactions. On the one hand, the reducing agent loses electrons and it oxidizes; on the other, the oxidizing agent adds electrons and is reduced.
Summarizing the development of redox reactions, we can say that the reducing agent yields electrons and increases their number of oxidation : that is, it oxidizes. The oxidizing agent, on the other hand, adds electrons and reduces its oxidation number (reduces).
Suppose a reaction occurs between chlorine and calcium . In this case, calcium acts as a reducing agent since it releases electrons and its oxidation number grows from 0 to 2 . Chlorine, on the other hand, acts as an oxidizing agent (sum of electrons).
It is important to keep in mind that reduction and oxidation always develop simultaneously. Each time a reducing agent acts in a reaction , there is also an oxidizing agent. The reducing agent is one that oxidizes in the reaction and provides electrons.
He hydrogen , by example , is a reducing agent that is frequently used. It is possible to obtain metal of copper in a reaction where hydrogen oxidizes and releases electrons.
Let's look at a list of other of the most used reducing agents, to appreciate more clearly the different applications they may have:
* carbon monoxide : Used in metallurgy to reduce metal oxides. The temperature used to reduce the ore in the blast furnace (the structure manufactured to fuse and reduce iron ores for future foundry processing) amounts to approximately 900 ° C;
* aluminum : since it is a chemical element (more precisely, a non-ferromagnetic metal) with a lot of chemical affinity with oxygen, metallurgy uses it as a reducing agent, and also to achieve those metals that are especially difficult to reduce, such as lithium and calcium, among others, through process known by the name of aluminothermic;
* charcoal : Its hydrocarbon derivatives are also reducing agents, among which are propane, butane, methane and gasoline, as well as organic compounds such as carbohydrates and fats. In the combustion of glucose, for example, which takes place in our own cells, there is a reaction in which carbon acts as a reducing agent by changing its oxidation state;
* non oxidizable metals : in this category are phosphorus and sulfur;
* materials that have cellulose : here we can mention paper, wood and textiles;
* alkali metals : although much of the metals can be considered reducing agents, as with iron when oxidized by the oxygen , alkali metals stand out for their special action in this context. Some examples are lithium, rubidium, potassium and sodium;
* the sugars : they pass through combustion when oxygen oxidizes them at a certain temperature;
* formic acid : also known by the name of methanoic acid, it is an organic acid that has only one atom carbon, which is why it is considered the simplest of its group;
* hydrides : are binary compounds that result from the union of a chemical element (such as a metal or a nonmetal) and hydrogen atoms. It should be mentioned that in its composition there can be no Noble gases.
During the photosynthesis and in the revealed of printed photographs, among others processes , also reducing agents are involved.