Stöchiometrie

Stöchiometrie is a branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. The term originates from the Greek words "stoicheion" meaning element and "metron" meaning measure. It is based on the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, the total mass of reactants must equal the total mass of products.

Central to stoichiometry is the concept of the mole, a unit of amount that represents a specific number of particles, typically 6.022 x 10^23. Chemical formulas and balanced chemical equations are used to determine the mole ratios of reactants and products. A balanced chemical equation ensures that the number of atoms of each element is the same on both sides of the equation.

Using these mole ratios, chemists can predict the amount of product that can be formed from a given amount of reactant, or determine the amount of reactant needed to produce a specific amount of product. This is crucial for various applications, including chemical synthesis, industrial production, and analysis. For example, in the Haber-Bosch process for ammonia synthesis, stoichiometry is used to calculate the precise amounts of nitrogen and hydrogen gas required to maximize ammonia yield. Stoichiometric calculations also help identify the limiting reactant, which is the reactant that is completely consumed first and thus limits the amount of product that can be formed. Understanding stoichiometry is fundamental for anyone working with chemical reactions.