1. 3.8 Stoichiometry & Mole Ratios

2. Recipe for 24 brownies 1cup flour 4oz. chocolate 2 eggs 1cup sugar 1 cup flour + 4 oz. chocolate + 2 eggs + 1 cup sugar  24 brownies

3. How many eggs do you need to make 24 brownies? 12 brownies? 96 brownies? 2 eggs 24 brownies 8 eggs 96 brownies

4. 1 cup flour + 4 oz. chocolate + 2 eggs + 1 cup sugar  24 brownies If you were making brownies with this recipe, how many cups of sugar would you add to 16 eggs? What would happen in you used a different ratio of ingredients? 1 cup sugar 2 eggs 16 eggs 8 cups sugar

5. A balanced chemical equation is like a recipe: It tells you how much of each ingredient (reactant) is required to form a certain amount of product. The coefficients of a balanced reaction stand for: # of molecules / atoms or # of moles. The mole ratio is determined from the coefficients of a balanced reaction (see example).

6. Stoichiometry is the calculation of the amount of product(s) formed by a chemical reaction. It is a 3-step process: Grams A reacted Grams B produced Moles A reacted Moles B produced 1 3 2 Remember that stoichiometry requires a recipe: A balanced chemical equation. divide by molar mass A multiply by mole ratio multiply by molar mass B