The different substances present in nature interact with each other continuously . Things as common as lighting a match, dissolving a medicine in water or even our breathing obey what are known as chemical reactions.
In this article we will see some of the most common types of chemical reactions, as well as explanations about their mechanics and the effects that these interactions between molecules produce.
Chemical reaction: explaining the concept
By chemical reaction we understand all interaction between substances in which chemical bonds are generated or broken, generating new compounds. The initial compounds are the so-called reagents, while the result of the reaction are the products .
These reactions may be reversible in some cases, with the reagents returning to their previous state, but in other cases they are consumed, and the reaction is irreversible. As the reaction takes place, there is a moment when a balance between reagent and product is produced and the reaction ceases.
In any case, atoms are neither created nor destroyed but only transformed, as is the case with energy conservation. Chemical reactions are an example of how they can transform from being part of some molecules to being in others.
Main types of chemical reaction
There are many possible ways for compounds to interact with each other, with different characteristics and peculiarities. Some of the main types of chemical reactions between compounds are the following .
1. Synthesis or addition reactions
In this type of chemical reaction two or more substances are combined to form a single compound . The combination of metal and oxygen to form oxides is an example, since it gives rise to relatively stable molecules that in some cases can be used to manufacture materials that are common in our daily lives.
2. Decomposition reactions
Decomposition reactions are those in which a particular compound decomposes and divides into two or more substances. This is what happens for example when water is electrolysed, separating water into hydrogen and oxygen.
3. Displacement, replacement or exchange reactions
One of the types of chemical reactions in which one element of a compound passes into another due to its interaction . In this case the element passed on is attracted to the other component, which must be stronger than the initial compound.
4. Ionic reactions
This is a type of chemical reaction that occurs upon exposure of ionic compounds to a solvent . The soluble compound dissolves, dissociating into ions.
5. Double substitution reactions
This is a similar reaction to that of substitution , with the exception that in this case one of the elements that form one of the compounds passes the other one at the same time that this second compound passes to the first one one of its own components. It is necessary for the reaction to take place that at least one of the compounds does not dissolve.
6. Oxidation-reduction or redox reactions
The type of chemical reaction in which there is an exchange of electrons is called as such. In oxidation reactions one of the compounds loses electrons to the other, oxidising. The other compound would be reduced by increasing its number of electrons.
These types of reactions occur both in nature and artificially. For example, it is the type of reaction that makes us need to breathe (acquiring oxygen from the environment) or that plants carry out photosynthesis.
7. Combustion reactions
A type of extremely rapid and energetic oxidation, in which an organic substance reacts with oxygen . This reaction generates energy (usually heat and light) and can generate flames, usually resulting in a product in the form of a gas. A typical example is the combustion of a hydrocarbon or the consumption of glucose.
8. Neutralization reactions
This type of chemical reaction occurs when a basic substance and an acidic one interact in such a way that they neutralize each other forming a neutral compound and water.
9. Nuclear reactions
It is called as such all that chemical reaction in which a modification is provoked not of the electrons of the atoms, but of their nucleus . This combination or fragmentation will cause a high level of energy. The combination of atoms is called fusion, while their fragmentation is called fission.
10. Exothermic reactions
An endothermic reaction is a chemical reaction that causes the emission of energy . Generally, these energy emotions are at least in the form of heat, although in cases where explosions occur, kinetic energy also appears.
11. Endothermic reactions
Endothermic reactions are all those types of chemical reaction in which the interaction between elements absorbs energy from the medium , being the final product much more energetic than the reagents.
Do chemical reactions explain the world?
A reductionist view of reality could make us think that almost everything that happens in the world can be understood as chemical reactions. For example, the idea that human consciousness is actually the result of biochemical reactions in the brain is popular.
This way of thinking based on the interaction between subatomic elements, atoms and molecules (and their corresponding types of chemical reactions) is intuitive and easy to conceive, since starting from a series of relatively simple and identical elements in all parts of the cosmos, it is intended to explain the complexity of the phenomena that occur on a larger scale and that are linked to unique and unrepeatable contexts. We assume that in order to understand the complex, we must start with that which is not so complex and without which the rest of nature (including here the human) would not exist.
However, we must not forget that nature is too complex to be studied only through this part of science, in the same way that it would be insufficient to study it exclusively from physics. We must also pay attention to phenomena that occur at a macro level, to reach a degree of global understanding about what happens around us and in our own organism.
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