(STOY-KEE-AHM-EH-TREE) Stoichiometry (STOY-KEE-AHM-EH-TREE) Studies the amounts of reactants and products involved in reactions Based on the law of conservation of mass (balanced chemical equation)

“to produce” or “yield” Chemical Equations 2 H2 (g) + O2 (g) 2 H2O (l) coefficient Product(s) Reactants “Reactants with” “to produce” or “yield” State of matter

Chemical Equation Interpretation + O2 → 2 H2O Two molecules One molecule 2 moles 1 mole 2(2.02 g) 32.00 g 2 (18.02 g) 36.04 g reactants   36.04 g product Interpretation

Mole Ratio Conversion factor derived from the coefficients of a balanced chemical equation Example: Synthesis of iron(III) oxide from its constituent elements. ____Fe + ____O2  ____Fe2O3 Fill in the mole ratios by hand

Stoichiometry Roadmap Reaction: A  B Given Find

Example 1 How many grams of water can be produced by burning 325 g of octane (C8H18)?

Example 2 What mass of carbon dioxide is produced by the complete combustion of 100.0 g of pentane (C5H12)?

Example 3 How many grams of HNO3 are required to produce 8.75 g of nitrogen dioxide according to the following equation? Zn + HNO3 Zn(NO3)2 + NO2 + H2O