Chemistry: Chapter 11 Note Packet

Converting Limiting Reactants % Yield Basic (g A, L A, mol A, particles A) Using mole A  mole B (entire mole map) Limiting Reactants Finding LR and ER Finding Theoretical Yield % Yield Solving for Actual Yield, Theoretical Yield or % when given two of the three Finding Theoretical Yield using LR questions then solving for actual yield or %

Review Composition Stoichiometry 0.15 mol NaOH to grams Stoichiometry-The study of the quantitative relationships between chemical formulas, reactions, and equations Review Composition Stoichiometry 0.15 mol NaOH to grams 9.00 g MgCl2 convert to molecules of MgCl2 0.15 mol NaOH x 40.0 g NaOH = 6.0 g NaOH 1 mol NaOH 9.00 g MgCl2 x 1mol MgCl2 x 6.02x1023 = 95.3g MgCl2 1mol MgCl2

Ex: Combustion of Propane __C3H8 + __O2  __CO2 + __H20 In this chapter, we do reaction stoichiometry. The book says there are many different types of problems. However, we are going to condense the problems to one type. They are all gram, mole, atom, liter conversion problems tied into equations. Stoichiometry will be used to perform our equations. Ex: Combustion of Propane __C3H8 + __O2  __CO2 + __H20 C3H8 + 5 O2 3CO2 + 4H2O Thus, for every 1 mole propane 5 moles oxygen are required to produce 3 moles of carbon dioxide and 4 moles of water.

What equalities can you get from the equation? (6) C3H8 + 5 O2 3CO2 + 4H2O

Use the equalities Ex1: 3 moles propane to moles of water Ex2: 6 moles of oxygen to moles of water Ex3: 20 moles of carbon dioxide to moles of propane

Mole to mole wks

New Mole Map

Synthesis of Hydrogen and Oxygen….. Three Core Steps: 1. Go to moles of “A” (A is whatever substance you start with) 2. Mole to Mole (Change from “A” to “B”)(B is new substance) 3. Go away from moles of “B” Note: Step 2 is always present!! A ____________ chemical equation is necessary! Synthesis of Hydrogen and Oxygen….. Ex 1: How many moles of water vapor are created from 2 moles of hydrogen?

Ex2: How many grams of water vapor are created from 64 Ex2: How many grams of water vapor are created from 64.0 grams of Oxygen? Ex3: How many liters of H2O are made from 5.00 L of Oxygen

Avagadro’s hypothesis makes it easier - “Equal volumes of gases at equal pressures and equal temperatures have equal # of particles.” So... two gases at 20 C, 1 atm, and 22.4 L each have 6.02 x 1023 molecules.   Combustion of C5H12 Ex4: How many Liters of Oxygen are needed to react with 14.40 g C5H12?

Lithium hydroxide reacts with carbon dioxide to produce Lithium carbonate and water Ex5: How many grams of solid lithium hydroxide are needed to react with 8.50 grams of carbon dioxide gas? Ex6: How many grams of water are produced from 2.00 moles of carbon dioxide and excess amount of lithium hydroxide Ex7: How many moles of lithium carbonate are produce from 152 grams of carbon dioxide and an excess amount of lithium hydroxide?

How many sandwiches can we make? What is left over? Problem: We want to make ten ham, egg, and cheese sandwiches. Each sandwich will be composed of two slices of bread, three slices of cheese, one egg, and one slice of ham. We have the following items: 10 slices of bread 25 slices of cheese 12 eggs 10 slices of ham

How many sandwiches can we make with what we are given? 1)What limits us in making ten sandwiches? 2) How much of the excess reactants do we have?

When one of the reactants runs out the reaction is over Limiting Reactant – A) the reactant that runs out first B) determines the amount of product that can be formed by a reaction. Excess reactant – not completely used up during a reaction (i.e. left over)

How to determine which reactant is the limiting reactant How did you do it with the sandwiches? Determine how many sandwiches you could make with each of the ingredients Lowest # of sandwiches produced was a result of the limiting reactant

9.3 Limiting Reactant Problems and % Yield... Ex1: How many grams of Magnesium Chloride can be made from 3.64 g of magnesium and 7.10 g of Chlorine gas? (It’s a synthesis reaction) Ex1a: What is the Limiting Reactant?  

9.3 Limiting Reactant Problems and % Yield... Ex2: How many moles of CO2 can be made from 2.70 moles of Ethene (C2H4) and 6.30 mole of oxygen? (It’s a combustion reaction) Ex2a: What is the Limiting Reactant?  

% yield = actual yield x 100 theoretical yield Ex1: What is the percent yield if a reaction produces only 75 moles of carbon dioxide when the theoretical yield was 95 moles of carbon dioxide? 1a- limiting reactant? Ex2: If a reaction produces a 70% yield and the reaction should have produced 85g of methane, how much methane was actually produced? 2a- limiting reactant?

Put it all together Ex3: Reacting 4.20 grams of Nitrogen with 0.800 g of Hydrogen produces______g of NH3 if there is a 75.5 % yield? A) What is the theoretical yield? _________ grams of NH3. B) What is the limiting reactant? C)What is the actual yield given a 75.5% yield?

Put it all together Ex4: How much hydrogen gas is produced when 6g of HCl and 5g of Mg react? What is the LR? If 2.4 moles should be produced by this reaction what is the % Yield? (hint: single replacement reaction)