Stoichiometry Warmup
• I have 1 mole of CO2 gas at STP.
• How many grams of CO2 do I have?
• How many Liters of CO2 do I have?
• How many molecules of CO2 do I have?
Stoichiometry
• The relationship between reactants and products in a balanced chemical equation
• Mole Ratios
Stoichiometry
• If you know the moles of a substance, the balanced equation allows you to determine the moles of all other substances in the rxn
Stoichiometry
• Coefficients from balanced equations can be used to write conversion factors called mole ratios
Stoichiometry
• Write a balanced equation for the following rxn:
• Hydrogen + nitrogen ammonia
Stoichiometry
• How many moles of ammonia are produced when 0.60 mol of nitrogen reacts with hydrogen?
Stoichiometry
• How many moles of hydrogen gas are needed to react with 0.60 mol of nitrogen gas?
Stoichiometry
• How many grams of ammonia are produced by the reaction of 5.40g of hydrogen with excess nitrogen?
Stoichiometry
• How many grams of nitrogen are needed to react with 5.40g of hydrogen?
Stoichiometry
Stoichiometry
• How many molecules of oxygen are produced when 29.2g of water are decomposed?
Limiting vs. Excess Reagents
• Limiting Reagent =The reactant that determines the amount of product formed in a rxn.
• Completely consumed in the rxn.
Limiting vs. Excess Reagents
• Excess Reagent = the reactant that is not completely used up
Limiting vs. Excess Reagents
• If you have 6.70 mole of Na and 3.20 mol Cl2, which is the LR?
• How many moles of NaCl is produced?
• How many moles of ER remain?
Limiting vs. Excess Reagents
• What is the limiting reagent when 80.0g Cu reacts with 25.0g S?
• What is the maximum amount of Cu2S in grams that can be formed?
• How many grams of ER remain?
LR video
• http://education-portal.com/academy/lesson/limiting-reactants-calculating-excess-reactants.html#lesson
Yield Video
• http://education-portal.com/academy/lesson/calculating-reaction-yield-and-percentage-yield-from-a-limiting-reactant.html#lesson
Theoretical Yield
• Theoretical Yield = maximum amount of product that can be formed from given amounts of reactants
• (based on calculation from the LR)
Actual Yield
• Actual Yield = the amount of product formed when the rxn is carried out in the lab
• Based on experimentation
Percent Yield
• Percent Yield = • actual yield / theoretical yield• x 100
Percent Yield
• What is the percent yield of CaO when 24.8g of CaCO3 is heated and 13.1g CaO is produced in the lab?
• CaCO3 CaO + CO2
Stoichiometry Review
What is the LR?
• 4 moles of oxygen gas react with 16 moles of H2 gas.What is the LR?
• What is the theoretical yield of product?
What is the percent yield?
• The burning of 18.0g of carbon in oxygen produces 55.0g of carbon dioxide.
Review Question
• Write a balanced equation for the reaction that occurs when Magnesium metal reacts with Hydrochloric acid.
Review Question
• If 10.0g of Magnesium is mixed with 35.0g of Hydrochloric acid, what is the LR?
Review Question
• What is the theoretical yield of magnesium chloride?
Review Question
• What is the percent yield of Magnesium chloride if 35.0g is produced in the lab?
Review Question
• How much excess reagent remains?
