We explain what an oxidizer is, in what reactions it intervenes and some examples. Fuel and activation energy.
What is an oxidizer?
An oxidizer or oxidant is a substance or chemical compound that has the property of reducing itself, that is, of gaining electrons, when it is part of an electrochemical or chemical reaction oxide-reduction. Is about chemical compounds that oxidize others with which they react, removing electrons from them.
In this type of reaction, known as redox, the two processes occur simultaneously: the oxidation of one compound (the fuel) and the reduction of the other (the oxidizer). All the compounds involved have a state of oxidation, and is usually released Energy while the reaction occurs, that is, it is a exothermic reaction. The classic example of this type of reaction is the combustion.
The best known oxidizer of all is oxygen, essential in practically all forms of combustion, and present in the atmosphere terrestrial in proportions of up to 21%. It is for this reason that we cannot light a fire without a minimum presence of air, because the air is a mixture oxygen and other gases.
Examples of oxidizer
Some known oxidizing or oxidizing agents are as follows:
- Oxygen (O). It is the most common oxidizer in the planet Earth. In fact, we use it in our body to oxidize the molecules glucose from food and thus obtain chemical energy To keep us alive
- The bleaches. Such as hypochlorite (ClO–) and other hypohalites, as well as chlorites (ClO2–), chlorates (ClO3–) and similar halogen compounds.
- Hydrogen peroxide. Known as hydrogen peroxide (H2O2).
- Permanganate salts. For example, potassium permanganate (KMnO4).
- Sulfoxides. For example, peroxosulfuric acid (H2SO5).
- Tollens' reagent. An aqueous complex of diamine-silver that is used in laboratories, precisely, as an oxidant.
- Most compounds containing Cerium (IV).
Oxidizer and fuel
Oxidizer and fuel participate in the redox reaction.If the oxidizer is the compound that gains electrons during the redox reaction, the fuel is the substance that gives up electrons and oxidizes, unlike the oxidizer (which is reduced).
In doing so, the fuel releases part of its chemical energy as heat, thus allowing combustion to occur, for example. Both fuel and oxidizer are essential for this type of chemical reactions.
Some typical fuels are coal, wood, hydrocarbons, gasoline, natural gas, etc.
Activation energy
Activation energy is a minimum initial energy charge that triggers the reaction. It is the last element necessary for combustion to occur, apart from fuel and oxidizer.
By themselves, fuel and oxidizer do not usually react, but if we add an additional load of energy, in the form of heat, we will unleash the combustion until the fuel has been consumed.
A clear example is the lighting of a campfire. We have the fuel (the wood), the oxidizer (the oxygen in the air), but we need to light a match or match to be able to start the combustion.
The same happens with a lighter: we have the fuel (the liquefied gas), the oxidizer (the oxygen in the air) and we only require the additional energy of the spark, produced by the rotation of the wheel on the lighter.