Presentation on theme: "II. Stoichiometry in the Real World * Limiting Reagents"— Presentation transcript:
1II. Stoichiometry in the Real World * Limiting Reagents More Stoichiometry!II. Stoichiometry in the Real World * Limiting Reagents
2X A. Limiting Reactants Available Ingredients 4 slices of bread 1 jar of peanut butter1/2 jar of jellyLimiting ReactantbreadExcess Reactantspeanut butter and jelly
3X Jam Sandwich Equation 2 loaves bread + 1 jar of jam 20 sandwiches Mole Ratio 2 : 1 : 20What would happen if we had 1 loaf of bread and 1 jar of jam?Bread = limiting reactantJam = excess reactant (1/2 jar left)Produce 10 sandwiches
4Limiting Reactantused up in a reactiondetermines the amount of productExcess Reactantadded to ensure that the other reactant is completely used upcheaper & easier to recycle
5Example 1 2 Fe (s) + O2 (g) 2 FeO (s) Iron burns in air to form a solid black oxide (FeO). If you had 50.0 g of iron and 60.0 g of oxygen, what is the limiting and excess reactant? How much iron oxide could be produced?2 Fe (s) + O2 (g) 2 FeO (s)
62 Fe (s) + O2 (g) 2 FeO (s) mass = 50 g mass = 50 g mass = 60 g
7Example 2 Zn + 2HCl ZnCl2 + H2 79.1 g mass = ? 0.90 L 2.5M 79.1 g of zinc react with 0.90 L of 2.5M HCl. Identify the limiting and excess reactants. How many grams of zinc chloride would be produced?Zn HCl ZnCl H279.1 g0.90 L2.5Mmass = ?
8Zn HCl ZnCl H2mass = 79.1 gV = 0.90 L of 2.5Mmass = ?
9Example 2 Results Limiting reactant: HCl Excess reactant: Zn Product Formed: x g ZnCl2left over zinc
10Student Example CaCO3 + 2 NaCl CaCl2 + Na2CO3 Sodium carbonate is needed in the manufacturing of glass, but very little occurs naturally. It can be made from the double replacement reaction between calcium carbonate and sodium chloride. If you had 5.00 g of each what is the limiting and excess reactant? How much sodium carbonate would be formed?CaCO NaCl CaCl2 + Na2CO3
16When 45. 8 g of K2CO3 react with excess HCl, 46. 3 g of KCl are formed When 45.8 g of K2CO3 react with excess HCl, 46.3 g of KCl are formed. Calculate the theoretical and % yields of KCl.K2CO3 + 2HCl 2KCl + H2O + CO245.8 g? gactual: 46.3 g