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Qualitative & Quantitative Gas Stoichiometry and Determination of an Unknown Alkali Carbonate

Qualitative & Quantitative Gas Stoichiometry and Determination of an Unknown Alkali Carbonate
Contributors
Jessica D'eon
University of Toronto, St. George Campus
Kris Quinlan
University of Toronto, St. George Campus
Beyond Benign
Beyond Benign, Inc.
Learning Objets
Summary
This experiment looks at two types of chemical reactions that produce hydrogen and carbon dioxide gases. It explores both qualitative observations (no measurements or numbers involved) about the reactions, as well as quantitative measurements of the volume of gas produced to explore concepts of stoichiometry and the ideal gas law. These concepts will be used to relate the stoichiometry of gas produced to the molar mass of an unknown to identify which alkali metal salt it is. The experiment emphasizes green chemistry principles that are used in chemistry labs on a daily basis to reduce environmental impact.

This laboratory material is adapted with permission from the laboratory manual developed by Prof. Jessica D’eon and Prof. Kristine Quinlan at the University of Toronto for a first-year general chemistry experiment. It is further discussed in the publication: J. Chem. Educ., 2019, 96 (12), 2836–2844. DOI:https://doi.org/10.1021/acs.jchemed.9b00287
Keywords
Stoichiometry
Balancing Equations
Acid-Base Chemistry
Green Chemistry Metrics

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Moderation state
Published
Object Type
Laboratory experiment
Audience
High School (Secondary School)
Introductory Undergraduate
Published on
Green Chemistry Principles
Waste Prevention
Atom Economy
Less Hazardous Chemical Syntheses
Learning Goals/Student Objectives
In performing this experiment, a student will…
• balance reaction equations
• realize the atom economy (2.1%) and reaction mass efficiencies (0.041% to 1.8%) are very low even though the yield of the reaction is >80%.
• introduction to green chemistry metrics (atom economy, reaction mass efficiency (RME)) in comparison to reaction yield
Common pedagogies covered
Hands-on learning
Problem-based learning
Time required (if applicable)
2 Hours

Submitted by

John De Backere
Safety Precautions, Hazards, and Risk Assessment
Safety Reminders:
• You must wear eye protection (chemical splash goggles) at all times.
• When igniting the bubbles, keep the area around the beaker containing the bubble solution clear. Keep your face away from the container.
• Solutions of acids and bases can burn your eyes and skin. Prevent the solution from contacting your eyes and skin. If you get any on your body, rinse it immediately with plenty of water.
• Dispose of the acid waste in the designated container at the fume hood.
• Tie back long hair.
Teacher Recommendations or Piloting Data (if available)
This activity has been run a number of times at the University of Toronto with large first-year courses (>1000 students).
Digital Object Identifier (DOI)
https://doi.org/10.59877/UQRI1001

File (PDF, PPT, image, etc)

File (PDF, PPT, image, etc)
greener_gas_stoich_final_220622.docx
Creative Commons License
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.