Limiting Reagents Excess Reagents Percent yield

Slides:



Advertisements
Similar presentations
Chapter 3 Atomic masses Average atomic mass –Ex. What is the avg. atomic mass of a sample that is 69.09% amu and 30.91% amu? –0.6909(62.93amu)
Advertisements

Performing Calculations involving Limiting and Excess Reagents.
Limiting Reactants and Percent Yield
Limiting Reactants & Percent Yield
Chemical Quantities Chapter 9
Composition Stoichiometry. Mass Percentage mass of element in compound molar mass of compound x 100%
Stoichiometry, Limiting Reactants and Percent Yield
Ch. 9 Notes – Chemical Quantities
Chapter 9 Chemical Quantities. 9 | 2 Information Given by the Chemical Equation Balanced equations show the relationship between the relative numbers.
Percent Yield and Limiting Reactants
Limiting Reactants and Percent Yields
Limiting Reactants & Percent Yield
Limiting reagent, Excess reactant, Theoretical or Percent yield
Limiting Reactant and Percent Yield Limiting Reagent u If you are given one dozen loaves of bread, a gallon of mustard and three pieces of salami, how.
Limiting Reagent and Percent Yield
Limiting Reagent u The limiting reagent is the reactant you run out of first. u The excess reagent is the one you have left over. u The limiting reagent.
Limiting Reagents and Percent Yield
P ERCENT Y IELD. OBJECTIVE I can calculate percent yield of a reaction.
Cookies and Chemistry…Huh!?!? Just like chocolate chip cookies have recipes, chemists have recipes as well Just like chocolate chip cookies have recipes,
Empirical formula:.
Chemical Calculations
Cookies and Chemistry…Huh!?!? Just like chocolate chip cookies have recipes, chemists have recipes as well Just like chocolate chip cookies have recipes,
*Notice, kind of like the opposite of Percent Error.
1 STOICHIOMETRY TUTORIAL Paul Gilletti 2 Instructions: This is a work along tutorial. Each time you click the mouse or touch the space bar on your computer,
1 STOICHIOMETRY 2 General Approach For Problem Solving 1. Clearly identify the Goal or Goals and the UNITS involved. (starting and ending unit) 2. Determine.
1 STOICHIOMETRY 2 Sample problem for general problem solving. Sam has entered into a 10 mile marathon. Use ALL of the following conversions (ratios)
Stoichiometry Loose Ends: Limiting Reactants, Percentage Yield, and Percentage Error.
11-3 Limiting Reactants Reactions to this point have had one ingredient in excess. When you are given two or both reactant amounts, you have a limiting.
Stoichiometry and the Math of Equations Part 4: Percent Yield 1.
1 STOICHIOMETRY Mass - Mass TUTORIAL By: Dr. Paul Gilletti Mesa Community College Modified By: Dr. Rick Moleski Scott High School.
UNIT 6: STOICHIOMETRY PART 2: STOICHIOMETRY. KEY TERMS Actual yield - Amount of product was actually made in a reaction Dimensional analysis - The practice.
Stoichiometry. Information Given by the Chemical Equation  The coefficients in the balanced chemical equation show the molecules and mole ratio of the.
Limiting Reactants and Percent Yield Definitions The Limiting Reactant is the reactant that limits the amounts of the other reactants that can combine.
Chapter 9 Chemical Quantities. Copyright © Houghton Mifflin Company. All rights reserved. 9 | 2 Information Given by the Chemical Equation Balanced equations.
Percent Yield and Limited Reactants NC Essential Standard Analyze the stoichiometric relationships inherent in a chemical reaction.
1 STOICHIOMETRY TUTORIAL metry.ppt.
Ch. 9 Notes – Chemical Quantities
Chapter 12 Stoichiometry. 1. The part of chemistry that deals with the amount of substances involved in chemical reactions A. 3 basic steps to every stoichiometry.
II. Stoichiometry in the Real World Stoichiometry.
Theoretical yield vs. Actual yield. Suppose the theoretical yield for an experiment was calculated to be 19.5 grams, and the experiment was performed,
Stoichiometry Limiting Reagents Stoichiometry If the quantity of each reactant is given, you must determine which one is used up first. This is the Limiting.
1 STOICHIOMETRY TUTORIAL Paul Gilletti 2 Instructions: This is a work along tutorial. Each time you click the mouse or touch the space bar on your computer,
Limiting Reactants In a chemical reaction you often have two or more reactants and until now we have assumed that there has been enough of each reactant.
Ch. 9 Notes – Chemical Quantities Stoichiometry refers to the calculations of chemical quantities from __________________ chemical equations. Interpreting.
PERCENT YIELD. Percent Yield Percent yield is the ratio of actual yield of an experiment to theoretical yield. To find percent yield, you divide the actual.
Chapter 9, section 3, part 2 Percent Yield. Why percent yield?  Usually, not all the product possible is actually formed.  theoretical yield  maximum.
Stoichiometry & Limiting Reactants. Stoichiometric Calculations The coefficients in the balanced equation give the ratio of moles of reactants and products.
Ch. 9 Notes -- Stoichiometry Stoichiometry refers to the calculations of chemical quantities from __________________ chemical equations. Interpreting Everyday.
Limiting Reactants & Percent Yield. Definitions  Limiting Reactant - completely consumed in the reaction and determines the amount of product formed.
It’s time to learn about... Stoichiometry: Limiting Reagents At the conclusion of our time together, you should be able to: 1. Determine the limiting.
Limiting Reactants, Theoretical Yield, and % Yield.
GOOD AFTERNOON! Prepare to take notes. You will be allowed to use these notes on the test next week! You will need: 1.Something to write on 2.Something.
SOL Review 6 Stoichiometry. Consider: 4NH 3 + 5O 2  6H 2 O + 4NO Many conversion factors exist: 4 NH 3 6 H 2 04NO 5O 2 (and others) 5 O 2 4 NO4 NH 3.
Mass-Mass Conversions 56.0 g N 2 x g N 2 g NH = 1904 = When nitrogen and hydrogen react, they form ammonia gas, which has the formula.
Calculating Quantities in Reactions
STOICHIOMETRY TUTORIAL
Stoichiometry and the Mole
Chemistry Limiting Reactions.
Limiting & Excess Reactants
Combustion Analysis A g sample composed of C, H, N is burned to produce g CO2 and g H2O Assume all C in the sample is converted to CO2.
STOICHIOMETRY TUTORIAL
STOICHIOMETRY TUTORIAL
Theoretical Yield.
Ch. 9 Notes -- Stoichiometry
Stoichiometry & Limiting Reactants
Chemical Reactions Limiting Reagent.
Bell Work: Limiting Reactant Problems
#5 of 11-6 LIMITING REAGENT SET
Stoichiometry Presentation
Presentation transcript:

Limiting Reagents Excess Reagents Percent yield

Limiting Reagents The limiting reagent is the reactant that runs out first Limits the amount of product that can be formed Take both reactants to the same product The answer is always the smallest amount of product

4 KO2(s) + 2H2O(l) g 4KOH + 3O2(g) Example Potassium superoxide, KO2 is used in rebreathing gas masks to generate oxygen. 4 KO2(s) + 2H2O(l) g 4KOH + 3O2(g) If a reaction vessel contains 0.25 mol KO2 and 0.15 mol H2O what is the limiting reagent? How many moles of oxygen can be produced? Take both starting amounts to moles of oxygen, the limiting reagent is the one that produced the smallest amount. 0.25 mol KO2 | 3 mol O2 = 0.19 mol O2 | 4 mol KO2 0.15 mol H2O | 3 mol O2 = 0.23 mol O2 | 2 mol H2O This is the smallest amount of O2 therefore KO2 is the limiting reagent and this is the amount of O2 produced.

Excess Reagent The reagent (reactant) that is left over once the reaction stops. Extra reactant To determine the amount of left over (excess) reagent Take both reactants to same product. Find the difference between the two amounts of products Use that a the starting number and convert back to the excess reagent.

Example Potassium superoxide, KO2 is used in rebreathing gas masks to generate oxygen. 4 KO2(s) + 2H2O(l) g 4KOH + 3O2(g) If a reaction vessel contains 0.25 mol KO2 and 0.15 mol H2O what is the excess reagent? How many moles were in excess? Take both starting amounts to moles of oxygen, find the difference between the two amounts, convert back to the excess reagent 0.25 mol KO2 | 3 mol O2 = 0.19 mol O2 | 4 mol KO2 0.15 mol H2O | 3 mol O2 = 0.23 mol O2 | 2 mol H2O 0.23 – .19 molO2 | 2 mol H2O = 0.03 mol H2O | 3 mol O2 This is the smallest amount of O2 therefore KO2 is the limiting reagent and H2O is the excess reagent. This is the amount of excess

Percent Yield Is found using the formula: Actual Theoretical *100 The actual yield is what is actually produced in the lab The theoretical yield is what is supposed to be formed based on stoichiometry *100

Example Potassium superoxide, KO2 is used in rebreathing gas masks to generate oxygen. 4 KO2(s) + 2H2O(l) g 4KOH + 3O2(g) If a reaction vessel contains 0.25 mol KO2 and 0.15 mol H2O what is the limiting reagent? How many moles of oxygen can be produced? In the lab 0.15 mol of O2 were actually produced, what is the percent yield? Take both starting amounts to moles of oxygen, the limiting reagent is the one that produced the smallest amount. Divide actual yield by the theoretical yield based on limiting reagent. 0.25 mol KO2 | 3 mol O2 = 0.19 mol O2 | 4 mol KO2 0.15 mol H2O | 3 mol O2 = 0.23 mol O2 | 2 mol H2O For % yield, 0.15 / 0.19 *100 = 79% This is not the greatest % yield, this of the percentage as your test score. This is the smallest amount of O2 therefore KO2 is the limiting reagent and this is the amount of O2 produced.