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Students will use manipulatives that represent the ingredients for S'mores (graham crackers, marshmallows, chocolate bar) to determine the limiting and excess reactants (reagents) for making S'mores. The students will extend this to preparing hot dogs for guests at a party and then relate the concept to an actual chemical reaction.This lesson is modified from a lesson by Rick Moog (POGIL project) and in cooperation with Michelle Holdbrooks at Thompson High School.This lesson plan was created as a result of the Girls Engaged in Math and Science University, GEMS-U Project.
Primary Learning Objective(s):
The students will be able to determine limiting and excess reactants (reagents) given the amounts of two or more reactants.
Additional Learning Objective(s):
Students learn critical thinking skills because they must analyze their calculations. In typical limiting/excess reactant problems, students will do several calculations but they must be able to analyze the answers and determine what that information tells them about which reactant is limiting, which is excess, how much excess is used or how much remains, and how much product is actually formed.
31 to 60 Minutes
Materials and Resources:
S'mores Activity - manipulatives
brown craft foam, black craft foam, white puff balls (colored paper can be substituted for the craft foam and cotton balls or white paper cut in circles for the puff balls), 3.33 " x 4" labels
Actual S'mores (if school permits)
graham crackers, large marshmallows, milk chocolate morsels, microwave, paper plates
Technology Resources Needed:
Optional: computer, LCD projector, interactive whiteboard, document camera
This activity can be done as a large group by building brown rectangles, black rectangles, and white circles according to one of the baggies on the envelope guide in a document or PowerPoint. The teacher or a student can use an interactive whiteboard to move the pieces around to build the S'mores and have the class determine the limiting ingredient and the excess ingredients. A template has been provided to use as a guide.
The teacher will need to know chemical nomenclature, balancing equations, stoichiometry, limiting and excess reactants. The students will need to be familiar with chemical nomenclature, balancing equations, and basic stoichiometry.
Students who complete all three parts of the activity early can use the following websites as additional practice on stoichiometry and limiting and excess reactants (reagents).
Students who are struggling with this concept can use the following websites to review and continue practice on stoichiometry and limiting and excess reactants (reagents).
Each area below is a direct link to general teaching strategies/classroom
for students with identified learning and/or behavior problems such as: reading
or math performance below grade level; test or classroom assignments/quizzes at
a failing level; failure to complete assignments independently; difficulty with
short-term memory, abstract concepts, staying on task, or following directions;
poor peer interaction or temper tantrums, and other learning or behavior problems.