Stoichiometry is important because it explains the relationships of reactants and products in chemical reactions. Without stoichiometry, it would be impossible to determine how much of a certain chemical is needed to yield a result or what molar amounts of each reactant and product are present in a completed reaction.Continue Reading
Stoichiometry means "element measurement" in Greek and is also known as Mass Relations. The principles of stoichiometry are based on the Law of Conversation of Mass, the Law of Multiple Proportions, and the Law of Constant Composition. In order to satisfy all three laws, every chemical reaction and corresponding equation needs to have a set molar ratio for its reactants and products that explains how it proceeds to completion every time. Once determined, the molar ratio for an equation does not change as long as the equation itself is untouched and no other chemicals are added to the reaction.
Because the calculations in stoichiometry are based on molar ratios, the molar masses of the products can be used to determine theoretical yields and limiting reagents. Stoichiometry can also help determine the concentrations of solutions that were used, provided that enough variables are accounted for. A proper stoichiometric molar ratio functions forwards and backwards so that calculating values for the reactants can be performed if the corresponding values for the products are known.Learn more about Chemistry
Coefficients are the numbers placed before the reactants in a chemical equation so that the number of atoms in the products on the right side of the equation are equal to the number of atoms in the reactants on the left side. If a written chemical reaction were not balanced in this manner, there would be no information available regarding the relationship between the reactants and products. Also known as stoichiometric coefficients, these numerical values demonstrate that the number of atoms on either side of the equation are equal to each other.Full Answer >
Delta H denotes the change in enthalpy, or energy, between products and reactants in chemical reactions. The change in enthalpy across a chemical reaction is the standard enthalpy of formation of the products minus the standard enthalpy of formation of the reactants. The change in enthalpy, or delta H, is usually in the form of heat expressed in kilojoules per mole.Full Answer >
Help with stoichiometry can be found through various university chemistry departments, tutors, online forums and study groups. For example, the University of California, Davis offers an extensive explanation of stoichiometry on its ChemWiki website. The site includes sample equations and solutions, with explanations for how the solutions are derived.Full Answer >
The four main categories of stoichiometry problems are mass-mass, mole-mole, mass-volume and volume-volume problems. Stoichiometry is the study of chemical changes and the relationship of the reactants to the products.Full Answer >