Lesson 4: Stoichiometry
Duration of Days: 4
Lesson Objective
Define stoichiometry and explain its importance in chemistry.
Use balanced chemical equations to calculate quantities of reactants and products.
Identify and solve problems involving limiting reactants.
Calculate percent yield in chemical reactions.
How do we use balanced chemical equations to determine quantities of reactants and products?
What is a limiting reactant, and how does it affect the outcome of a chemical reaction?
Why do actual yields often differ from theoretical yields in chemical reactions?
Stoichiometry
Mole ratio
Limiting reactant
Excess reactant
Theoretical yield
Actual yield
Percent yield
NGSS HS-PS1-7: Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
Practice with multi-step problem-solving and quantitative reasoning.
Reinforce understanding of proportional relationships.
Develop skills in interpreting and analyzing chemical equations.
Students will learn to use balanced chemical equations to perform stoichiometric calculations, determine limiting reactants, and calculate percent yield. They will apply these concepts to real-world scenarios and engage in hands-on activities to reinforce their understanding.
To develop students' ability to quantitatively analyze chemical reactions and understand the relationships between reactants and products in terms of amounts and yields.
DOK 1: Recall stoichiometric principles and definitions.
DOK 2: Perform basic stoichiometric calculations.
DOK 3: Solve multi-step problems involving limiting reactants and percent yield.
Discuss how stoichiometry is used in pharmaceutical manufacturing to ensure proper drug dosages.
Explore how traditional fermentation processes in various cultures (e.g., making kimchi, yogurt, or beer) involve stoichiometric principles.
Analyze the role of stoichiometry in environmental chemistry, such as calculating carbon footprints or air pollution levels.
Students may confuse mole ratios with coefficients in balanced equations.
Some might think the limiting reactant is always the one with the smallest coefficient.
Students may struggle to understand why actual yield is often less than theoretical yield.
Provide step-by-step guides and worked examples for visual learners.
Use manipulatives or digital simulations to represent molecules in reactions for kinesthetic learners.
Offer tiered worksheets with varying levels of difficulty for practice problems.
Daily exit tickets with stoichiometric calculations.
Lab report on a reaction involving limiting reactants and percent yield calculation.
End-of-unit quiz covering all stoichiometric concepts, including multi-step problems.
Textbook: Chemistry
Digital balance for lab activity
Chemical reagents for hands-on experiments
Worksheets on stoichiometric calculations
Online simulation: PhET "Reactants, Products, and Leftovers"
Video: "Stoichiometry - Chemistry for Massive Creatures" (Crash Course Chemistry)