A reaction is he effect of a certain action. Chemistry, on the other hand, is the name given to the science oriented to the analysis of the composition, properties and changes of matter.
With these concepts clear, we can move forward with the definition of chemical reaction. This notion refers to alterations that, for various factors, can experience certain substances. A chemical reaction, therefore, causes a substance to acquire different properties, with changes in its links and its structure.
In short, the chemical reaction can be understood as the process that leads to a substance (called reagent) to transform into another with properties that are different. This second substance is known as product.
The chemical reaction involves the disappearance of certain properties and the emergence of others. The links that existed between the atoms of the reactants break, leading to atomic rearrangement and the formation of new bonds. That is why the substance resulting from the chemical reaction has different characteristics compared to the original substance.
Reactions develop differently depending on whether it is the organic chemistry Or the inorganic chemistry. It is possible to differentiate, on the other hand, between a endothermic chemical reaction (which implies the absorption of energy in the framework of the reaction) and the exothermic chemical reaction (the energy, in this case, is released).
It is important to note that, in all chemical reactions, the mass (the mass of the products is equal to the mass of the reactants) since the atoms are rearranged, but they are not eliminated or new ones are created.
One of the concepts related to the chemical reaction is the reaction speed, which is understood as the amount of substance that undergoes a transformation in a certain reaction for each unit of time and volume. To cite two opposite examples, butane can be transformed into fire through a combustion that takes less than a second, while the oxidation of iron can take several years. There are certain factors that have a direct impact on the speed reaction, such as the following:
* concentration: as exposed by the collision theory (the qualitative explanation of the way in which chemical reactions take place and the reason why the speed differs in each case) and is described by the speed law (the expression through which it is possible to calculate the reaction rate, and to relate it to the concentrations of the reactants), the higher the concentration, the faster the reaction rate. As the concentration of the substances that participate in the chemical reaction, so does the collision frequency (if the reacting particles do not collide, there can be no reaction);
* Pressure: since increasing the Pressure is the same as increasing the concentration of a gas, this can cause a gaseous reaction to occur more quickly. In the cases of reaction in a condensed phase, the impact of pressure is only significant when its value is very high;
* nature of the reactionSimply put, some chemical reactions take less time than others simply by their very nature;
* order: the degree to which pressure or concentration affects the rate depends on the order of the chemical reaction;
* temperature: Usually, when a reaction takes place, a temperature higher is reflected in higher energy input into the system, thus also increasing speed. The explanation for this phenomenon lies in the fact that, together with temperature, the amount of colliding particles increases. with the energy required for a successful chemical reaction.