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Stoichiometry Challenge

Stoichiometry Challenge
Contributors
Mollie Enright
Beyond Benign, Inc.
Annette Sebuyira
Retired K-12 Educator | Beyond Benign, Inc.
Janie Butler
Science Done Sustainably
Beyond Benign
Beyond Benign, Inc.
Learning Objets
Summary
This lesson introduces the concept of green chemistry by replacing a conventional aluminum to alum stoichiometry lab with a more sustainable precipitation reaction using sodium carbonate and calcium chloride. Green chemistry is an approach that aims to design chemical processes and products that minimize the use and generation of hazardous substances, while also reducing waste and improving efficiency. By using a greener alternative to the traditional lab, this lesson showcases the principles of stoichiometry, which involve calculating the theoretical yield based on the known concentrations and quantities of the starting materials in a balanced chemical equation.
Keywords
Stoichiometry
Dilutions
Molarity
Making Solutions
Double-Displacement
12 Principles of Green Chemistry

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Moderation state
Published
Object Type
Laboratory experiment
Audience
High School (Secondary School)
Published on
Green Chemistry Principles
Atom Economy
Less Hazardous Chemical Syntheses
Safer Chemistry for Accident Prevention
NGSS Standards, if applicable
• HS-PS1-2. Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.
• HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
• HS-PS1-10. Use evidence to support claims regarding the formation, properties and behaviors of solutions at bulk scales.
Learning Goals/Student Objectives
Educational Goal: Students will…
• Calculate the amounts of material to make aqueous solutions of CaCl2 and Na2CO3.
• Prepared solutions of CaCl2 and Na2CO3 to produce an assigned amount of CaCO3.
• Research where CaCO3 can be found nature.

Student Objectives: Students will…
• Synthesize an assigned amount of calcium carbonate.
• Demonstrate the mass-mass relationship in chemical reactions.
• Calculate the percent yield and analyze sources of error.
Time required (if applicable)
One 45-60 Minute Class Period

Submitted by

Sarah Prescott
Safety Precautions, Hazards, and Risk Assessment
Safety Information:
• Calcium chloride (CaCl2) and sodium carbonate (Na2CO3) are both skin irritants.
• If either chemical comes in contact with skin, wash with soap and water.
• If they come in contact with your eyes, spend 15 minutes in the eyewash.
• Consult manufacturer provided safety data sheets (SDS) for complete safety and handling information.

Digital Object Identifier (DOI)
https://doi.org/10.59877/VHQJ3248

File (PDF, PPT, image, etc)

File (PDF, PPT, image, etc)
stoichiometry_challenge.docx
Creative Commons License
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.