Presentation on theme: "New Section in Table of Contents"— Presentation transcript:
1New Section in Table of Contents Stoichiometry NotesNew Section in Table of Contents
2Real Life Application Ingredients 2 1/4 cups all-purpose flour 1 teaspoon baking soda1 teaspoon salt1 cup (2 sticks) butter, softened3/4 cup granulated sugar3/4 cup packed brown sugar1 teaspoon vanilla extract2 large eggs2 cups (12-oz. pkg.) NESTLÉ® TOLL HOUSE® Semi-Sweet Chocolate Morsels1 cup chopped nuts
3Real Life ApplicationWe cannot forget about the law of conservation of mass.The mass of what we put in must be equal to what we get out.KC 1: The excess reactants are all the leftover unused reactants. (The reactant that’s leftover).
4Particle and Mole Relationships Chemical reactions stop when one of the reactants is used upKC 2: Stoichiometry is the study of quantitative relationships between the amounts of reactants used and amounts of products formed by a chemical reactionSo based on how much reactant you put in you can calculate how much product you will get outQuick demo of baking soda.
11Using StoichiometryHow many grams of Fe2O3 are formed when g of iron reacts with excess oxygen using the balanced chemical equation below:4Fe(s) + 3O2(g) 2Fe2O3(s)
12Using StoichiometryKey Concept 5:How many grams of lithium nitrate will be needed to make 250 grams of lithium sulfate, assuming that you have an adequate amount of lead (IV) sulfate to do the reaction?____Pb(SO4)2 + ____LiNO3 ____Pb(NO3)4 + ____Li2SO4
13Using Stoichiometry ____NaOH + ____H2SO4 ____H2O + ____Na2SO4 Key Concept 6:How many grams of sodium sulfate will be formed if you start with 200 grams of sodium hydroxide and you have an excess of sulfuric acid?____NaOH + ____H2SO4 ____H2O + ____Na2SO41st hour
14Using Stoichiometry New Conversion Factor: 1 mol of gas = 22.4L (at STP = standard temperature and pressure)How many moles of sodium chloride are in 3.87 L?How many grams of sodium chloride are in 3.87L?
15Using Stoichiometry 4Fe(s) + 3O2(g) 2Fe2O3(s) Mol Fe Mole Fe2O3 L Fe2O3
16Using Stoichiometry ____NaOH + ____H2SO4 ____H2O + ____Na2SO4 Key Concept 7:How many liters of sodium sulfate will be formed if you start with 200 grams of sodium hydroxide and you have an excess of sulfuric acid?____NaOH + ____H2SO4 ____H2O + ____Na2SO4
17PracticeHow many grams of water are formed when .25L of propane (C3H8) burns at STP with excess oxygen according to the reaction below:_____C3H8 + ______O2 → ______CO2 + _______H2O
18PracticeHow many grams of CaCl2 are formed when 21.3g of Ca(OH)2 reacts with excess HCl?_____Ca(OH)2 + _____HCl ______CaCl2 + ______H2O
19PracticeHow many grams of BaCl2 are formed from moles of Ba(ClO3)2?_______Ba(ClO3)2 → _______BaCl2 + _____O2
20PracticeIron(III) oxide, Fe2O3, can be reduced to iron by passing carbon monoxide, CO, over the heated oxide. How many moles of iron can be produced from moles of iron (III) oxide and excess carbon monoxide?______Fe2O3(s) + _____CO(g) _____Fe(s) + _____CO2(g)
21PracticeButyne, C4H6, burns in the presence of oxygen in air to produce carbon dioxide, CO2, and water H2O. How many moles of oxygen will be required to produce moles of carbon dioxide?______C4H6 + ______O2 ______CO2 + ______H2O
23Limiting and Excess Reactants KC 8: If you have 2 givens in your problem, it is a limiting reactant problemKC 9: The reactant that produces the smallest amount of a product is the limiting reactant. This is the reactant that will be used up first in the reaction.
24ExampleHow many grams of Cu can be formed when g of Fe reacts with g of CuCl2?2 Fe CuCl2 3 Cu + 2FeCl3
25Steps for solving LR problems KC 10:Write down the givensUse molar mass to convert to molesUse mole ratio from the balanced equationConvert to desired unitThe correct answer is the smallest answer as the reaction will stop once one reactant is gone
26Limiting and Excess Reactant KC 11: 80.0g Cu reacts with 25.0g S. Determine which is the limiting reactant and calculate how much Cu2S is formed in grams?2Cu(s) + S(s) → Cu2S(s)
27Limiting and Excess Reactant KC 12: What is the limiting reactant if 65g of each reactant is present?___Zn + ___HCl → ___ZnCl2 + ___H2
28Excess and Percent Yield KC 13: To find how much excess you have you must take the limiting reactant and solve for the excess reactant. You need to look at what you are given versus what you need.
29Excess Reactant - Example How many grams of Cu can be formed when g of Fe reacts with g of CuCl2?2 Fe CuCl2 3 Cu + 2FeCl3CuCl2 – limiting reactant188.5g Cu is formedHow many grams of excess is left over?
31Percent Yield KC 14: % yield = actual yield x 100 theoretical yield KC 15: Actual yield must be found experimentally. It is recognized by words like “produced” and “formed”KC 16: Theoretical yield is done using stoichiometry. It is a prediction and will always be done using math.
32Percent YieldKC 17: A student calculated she should obtain 28g of a substance. In the experiment, 25g was produced. What is the percent yield of the experiment?
33Percent Yield - Example 167.4 g of Fe reacts with g of CuCl2 to form g of copper. What is the percent yield of copper?2 Fe CuCl2 3 Cu + 2FeCl3
34PracticeKC 18: 11.2g of nickel (II) sulfide reacts with 5.43g of oxygen producing 4.97g of nickel (II) oxide. What is the percent yield of this reaction?_____NiS2 + _____O2 → _____NiO + _____SO2
35PracticeKC 19: You are given 0.45g of Al(OH)3 and 0.55g of H2SO4. The reaction produces 0.15g of water. What is the percent yield of this reaction?____Al(OH)3 + _____H2SO4 → _____Al2(SO4)3 + _____H2O
36PracticeKC 20: You are given 3 moles of lithium and 3 moles of nitrogen. The reaction produces .5 moles of lithium nitride. What is the percent yield of this reaction?____Li + _____N2 → _____Li3N