Stoichiometry How does stoichiometry relate to a correctly balanced chemical equation?

What information can the coefficients of a correctly balanced chemical equations provide? Example: 2 H2(g) + O2(g)  2 H2O(g) The number of atoms / molecules that react with each other The number of moles of atoms / molecules that react The relative volume of gases that react (if reactants and products are gases)

Stoichiometry Use the coefficients of a balanced equation to determine the mole ratio among all participants in the reaction. Example: 2 H2 + O2  2 H2O There are 2 moles of H2 consumed and 1 mole of 02 consumed for every 2 moles of H2O produced If 4 moles of oxygen react with excess hydrogen, how many moles of water will be produced? 1 mole O2 = 2 mole H2O Set up a proportion or use dimensional analysis

Think About Units Carefully! The coefficients indicate the mole ratios and do not indicate mass ratios If grams are involved, you must convert between grams and moles Each 1 mol = _____ g from the PT Example based on: 2 KClO3  2 KCl + 3 O2 How many moles of KClO3 are required to produce 64 grams of O2? Step 1: Convert given mass of O2 to moles O2 Step 2: Use Coefficients to compare moles O2 to moles KClO3

Think About Units Carefully! Example based on: 2 KClO3  2 KCl + 3 O2 How many grams of O2 are produced if 0.50 mol of KClO3 react completely? Step 1: Use Coefficients to compare moles KClO3 to moles O2 Step 2: Convert moles of O2 to grams of O2

Challenge Question: Based on: 2 KClO3  2 KCl + 3 O2 How many grams of O2 will be produced if 2.38g of KClO3 completely react? Step 1: Convert given mass of KClO3 to moles KClO3 Step 2: Use Coefficients to compare moles KClO3 to moles O2 Step 3: Convert moles O2 to grams of O2