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A Green(er) Redox Reaction

A Green(er) Redox Reaction
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
Green chemistry is an approach to practicing chemistry that strives to reduce or eliminate the use and generation of hazardous substances. This focus on safety and environmental responsibility must always refer to a baseline measure, meaning that reactions can never be “green” but instead can always be “greener”.

This lab provides a great example of a greener approach to teaching reduction-oxidation (redox) reactions by replacing the traditional quantitative redox reaction between solid copper and aqueous silver nitrate. Typically, this lab is done at the end of a large unit covering different types of reactions and stoichiometry. This exercise will be used to show a redox reaction between solid magnesium metal and an aqueous solution of zinc chloride. The students will calculate the theoretical yield and using that information calculate the percent yield. The products are zinc metal and aqueous magnesium chloride.
Keywords
Green Chemistry
Redox Reactions
Single-Displacement
Chemical Reactions
Stoichiometry
Chemical Equation
Percent Yield
Theoretical Yield

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Moderation state
Published
Object Type
Laboratory experiment
Audience
High School (Secondary School)
Published on
Green Chemistry Principles
Waste Prevention
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-PS1-12. Use evidence to illustrate that some chemical reactions involve the transfer of electrons as an energy conversion occurs within a system.
Learning Goals/Student Objectives
Educational Goals: Students will understand…
• The process of oxidation-reduction.
• How to carry out stoichiometric calculations to find the theoretical yield of a product.
• Use actual data to calculate percent yield.

Student Objectives: Students will…
• Look at an oxidation-reduction reaction in a single displacement reaction.
• Calculate theoretical results through stoichiometry and calculate percent yield.
• Compare the toxicity data between the zinc/magnesium chloride reaction and the more traditional example of copper and silver nitrate.
Common pedagogies covered
Hands-on learning
Time required (if applicable)
Two 45-50 minute class periods

Submitted by

Rhianna Kozinski
Safety Precautions, Hazards, and Risk Assessment
Safety Information:
• Before handling, review manufacturer provided safety data sheets for full handling and safety information.
• Zinc chloride (ZnCl2) has serious health warnings. If it comes into contact with the skin, it needs to be washed with soap and water for several minutes. If it comes into contact with the eyes wash for 15 minutes in the eyewash and seek immediate medical attention. All appropriate protective equipment should be worn when handling zinc chloride, including lab goggles, gloves, and a lab coat.
• Magnesium metal is a flammable solid. Keep away from heat and ignition sources.
• Magnesium chloride is not a hazardous substance.
• Zinc metal is not a hazardous substance.

Disposal Information:
• Though products in this lab are not hazardous, waste should be disposed of as hazardous waste in the event that all zinc chloride has not fully reacted.
Digital Object Identifier (DOI)
https://doi.org/10.59877/ZSCA5729

File (PDF, PPT, image, etc)

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