Stoichiometry refers to the numerical relationship that exists between the masses of the elements that make up a substance.
The first thing we are going to do is know the etymological origin of the term stoichiometry . Specifically, we have to establish that it is a neologism that derives from Greek since it is the result of the sum of three lexical components of said language such as these:
-The word “stoicheion”, which is used to refer to a basic element that is part of a series that is ordered.
-The noun “metron”, which is synonymous with “measurement”.
-The suffix “-ia”, which indicates “quality”.
In our language the term became stoichiometry , an idea that is used in the field of chemistry .
What is stoichiometry
The numerical bond established between the masses of those elements that make up a substance is called stoichiometry. The proportion recorded in the elements that combine in the development of a chemical reaction is also called stoichiometry.
It can be noted that stoichiometry consists of calculating, quantitatively, the relationships established by the products and the reactants within the framework of a reaction. The German Jeremias Benjamin Richter defined stoichiometry at the end of the 18th century , referring to the study of the “mass relations” or “quantitative proportions” of the elements involved in a reaction.
The idea of stoichiometry can be used with reference to the quantitative proportions of those elements involved in a chemical reaction.
Aspects determined by Richter
Precisely as a result of this work, several fundamental aspects or precepts were determined, such as the following:
-Matter is made up of atoms and vacuum.
-No less relevant is that he established that chemical elements are substances that are made up of equal atoms.
When a chemical reaction occurs, the substances involved undergo a transformation : the reactants lead to the appearance of products. In the process, however, the number of atoms is not modified.
Stoichiometry and chemical equations
The written representation of a chemical reaction is called a chemical equation , which uses chemical symbols to identify atoms and the way they are grouped. In this context, the stoichiometric coefficient is the number of molecules of a certain type that participate in the equation.
In the same way, we cannot ignore that what is known as the algebraic balancing method or the method of balancing redox equations, which are other ways of carrying out the determination, is of great relevance within stoichiometry. of the material balance.
A balanced chemical equation , on the other hand, appears when the law of conservation of matter (which indicates that the number of atoms is equal in the reactants and products) is respected. Taking this principle into account, stoichiometric calculations are based on the fixed combination bonds that maintain substances in a balanced chemical reaction. The unit that relates the masses of reactants and products in a stoichiometric calculation is the mole .
In addition to the mole, we cannot forget to mention another series of elements and compounds that are of great relevance in stoichiometry. We are referring, for example, to the atomic mass scale, to the average atomic mass, to the so-called molar mass, to the molecular weight and also to what is known as formula weight.