4.3 Reaction Stoichiometry A balanced chemical equation may be used to describe a reaction’s stoichiometry (the relationships between amounts of reactants and products). Coefficients from the equation are used to derive stoichiometric factors that subsequently may be used for computations relating reactant and product masses, molar amounts ... empirical formula 3. take the molar mass of the molecular formula (given in the problem) and divide it by the molar mass of the empirical formula. This will equal the number of times the e.f. is in the m.f. 4. distribute the number attained through the empirical formula Example: 2(C 2 H 5) = C 4 H 10 Calculating the Formula of a Hydrate 1. 3-1 Stoichiometry of Formulas and Equations Chapter 3 Subscribe to view the full document. 3-2 Chapter 3 Stoichiometry of Formulas and Equations Objectives Understand these concepts: The Mole, relation to mass, formulas, equations Writing and balancing chemical equations Limiting Reactants, Percent yields Solution stoichiometry, Molarity

The empirical formula for this compound is thus CH 2. This may or not be the compound’s molecular formula as well; however, additional information is needed to make that determination (as discussed later in this section). Consider as another example a sample of compound determined to contain 5.31 g Cl and 8.40 g O. Chapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations John D. Bookstaver St. Charles Community College Cottleville, MO Lecture Presentation