Introduction To Stoichiometry

Introduction to Stoichiometry

What does stoichiometry mean? Before trying to understand what stoichiometry means, you first need to know what chemistry deals with. Chemistry is a branch of science that deals with matter and all the change in composition it undergoes. Now, along the long line of the history of chemistry, scientists have used symbols, formulas, and equations to indicate the elements present, the relative amounts of elements, and the variety of combinations of atoms during a chemical change. As a bonus, you can also find out how much product will be formed or how much reactant is needed, based on the masses of the substances involved. The science that deals with the manipulation of said variables is called Stoichiometry. Stoichiometry,

Lomonosov (in 1756) and Antoine Lavoisier (in 1774). This law states that, “Mass is neither gained nor lost in a chemical reaction, or the total mass of the reactants (consumed) during a chemical reaction is equal to the total mass of products formed.” The Law of Constant (definite) Proportion: This law was stated by a French chemist, named Joseph Louis Proust in 1799. This states that, “The same chemical compound always contains same elements combined together in definite proportion by weight regardless of the origin of the compound.” Law of Multiple Proportion: This law was stated by John Dalton in 1803. It states that, “When one element combines with another element to form two or more different compounds, then the weights of one of the elements which combine with the constant weight of the other bear a simple whole number ratio to one another.” Law of Reciprocal (equivalent) Proportion: This law was stated by Richter in 1792. It states that, “When two different elements combine separately with the same weight of the third element, the ratio in which they do so will be the same or simple multiple ratio in which they unite with each

The same can be said for atoms. The mass of atoms in atomic mass units (amu) is called atomic mass. On average, the mass of a single hydrogen atom is 1.00794 or 1.01. But, "Where does this value base on?" you may ask. This is based on a single atom of carbon-12. A hydrogen atom is approximately 1/12 the mass of a carbon atom. The average mass of a single fluorine atom is 18.9984032 amu, which can can be rounded off into 19.00. These are only 3 of the many atomic masses present. We only talk of average masses here because many elements consist of mixtures of atoms that have identical chemical properties but differ in mass. We will later dwell on this topic later on "Isotopes." You can also use atomic weight (this unit does not have an abbreviated form), but it is advised to stick with atomic mass, for accuracy and