Step into the Generalities in Chemistry, where the foundations of this diverse field are explored. Delve into the fundamental principles and concepts that underpin the study of matter and its transformations. From atomic structure and chemical bonding to states of matter and chemical reactions, uncover the key elements that shape our understanding of chemistry. Embark on a journey of discovery as you unravel the secrets and intricacies of this fascinating science.
What is Proust’s law? Proust’s law or law of definite proportions can be stated as follows: When two elements combine to give rise to another compound, they always do so in a constant mass ratio. In 1799, the French chemist Joseph Louis Proust (1754-1826) found in different samples of a compound the same elements in … Read more
What is Lavoisier’s law? Lavoisier’s law or the law of conservation of mass explains that during a chemical reaction there is no change of mass, i.e. the sum of the mass of the reactants (before the reaction takes place) is equal to the mass of the products (after the reaction takes place). It can be … Read more
Dalton’s law Dalton’s law or the law of multiple proportions can be stated as follows: When two elements combine to form more than one compound, a constant mass of one of them combines with variable masses of the other. These variable masses have a simple integer relationship to each other. In 1803, the English chemist … Read more
A molecule is an aggregate of at least two atoms in a definite placement that are held together by chemical forces (also called chemical bonds). A molecule can contain atoms of the same element or atoms of two or more elements, always in a fixed ratio. Thus, a molecule is not always a compound, which, … Read more
What is a mole? In chemistry, quantities of substances are traditionally measured in volume or mass. Thus, the concept of mole (symbol mol) is very important, since it allows stoichiometric calculations in chemical reactions. In this way, we can indicate what ratio exists between reactants and products. For example, in the reaction of nitric acid formation, one mole … Read more
A chemical change is a variation in the internal structure of a compound, to the point that it will be different from its origin. Moreover, this type of change is usually irreversible. A chemical change is a change in the nature of the substance. It is a profound modification that implies transformations in the composition … Read more
On our planet, matter is essentially present in three different forms or states of aggregation: the solid state, the liquid state and the gaseous state. Each of them presents observable properties that are characteristic of it. Thus, solids have their own shape and volume; liquids, on the other hand, although they adopt the shape of … Read more
Substances are characterized by their properties and by their composition. Color, melting point and boiling point are physical properties. A physical property can be measured and observed without changing the composition or identity of the substance. On the other hand, the statement “gaseous hydrogen burns in the presence of gaseous oxygen to form water” describes … Read more
Chemical Element and Chemical Compound Matter is made up of tiny units called atoms. A chemical element is a substance made up of only one type of atom. Approximately 90 of these elements can be found in nature. The rest do not occur naturally and can only be obtained artificially. Chemical compounds are substances in … Read more
As you will remember, matter is everything that surrounds us, everything that has mass and occupies a place in space. Chemistry is the science that studies matter, its properties, its qualitative and quantitative constitution, the changes it undergoes, as well as the energy variations that accompany the transformations in which it is involved. Since ancient … Read more
