Stoichiometry

Combustion, Fuels, and Green Chemistry Metrics 


Module Overview

This module connects ideas across topics in a first semester introductory chemistry course to explore the impacts of combustion reactions. By motivating students to understand the relationship between reaction completion and yield, and molar enthalpies and reaction efficiency in the context of selecting fuels for a fire, educators can explore both safety and sustainability without additional materials.

Each of the two units focuses on a different green chemistry principle. The first examining stoichiometry explores the impacts of low yields such as carbon monoxide from incomplete combustion. By exploring the impacts of incomplete combustion we can examine the downstream effects and importance of waste prevention. Using GCP #2 Atom Economy students evaluate the impacts of reactants forming byproducts and waste products from reactions. Also in the second unit students work to select appropriate fuels for a given context and compare fuel efficiency metrics. 

 

Module Goal

Students will be able to balance chemical reactions, identify limiting reagents, and apply and evaluate a variety of reaction metrics including yield and mass efficiencies. Students will discuss and practice determining the products of complete and incomplete combustion, and identify potential impacts of combustion on the environment. 

Audience

First-year general chemistry undergraduates

Class Time Requirement

These materials can be used to prepare two lectures, two assignments, two in class group activities, and two assessments; roughly 1 week of a 14 semester class or 3 hours of weekly instruction. 

Module Authors

Julian Silverman, Fashion Institute of Technology; Jessica D’eon, University of Toronto

Module Summary

Assumed Prior Knowledge

Students should be able to demonstrate the following skills and concepts to successfully begin this module:

  • Knowledge: Students should be familiar with the following before this module: molecular formulas, molar mass, identifying chemical reactions. 
  • Skills: Students should be comfortable converting between mass and amounts using molar masses, performing mass balances and determining the stoichiometric ratios for a balanced reaction. 

Learning Objectives

Students will be able to:

  1. Discuss combustion and basic fire safety.
  2. Use balanced reactions to relate the amounts of reagents and products.
  3. Evaluate the impacts of combustion.
  4. Calculate the yield of a reaction.
  5. Assess processes using efficiency metrics.

Special Resources

This module is designed to be low-tech and flexible for instructors. Lecture materials may be provided as handouts or posted online in advance of class. Open-access resources are used to contextualize lecture material and the assignment. 

Unit Overview

 

Unit 1: Relating Reagents and Products

 

1.1

Lecture 1 - The Fire Triangle (30 minutes). Background information on reactants in combustion and basic fire safety

1.2

Activity 1 - Products of Combustion (30 minutes). Group activity focused around calculating the masses of different products from complete and incomplete combustion.

Unit 2: Yield and Efficiency Metrics

 

2.1

Lecture 2 - Alternative Fuels (30 minutes) - Background information on fuels, and mass efficiency metrics

2.2

Activity 2 - Evaluating Fuel Production (45 minutes) - Group activity focusing on calculating efficiencies of different ways to generate hydrogen fuel.

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Stoichiometry Includes:

  • Module Overview Document
  • Units 1-2
  • Formative Assessments
  • Summative Assessments

UN SDGs

This module references the following U.N. Sustainable Development Goals (SDGs):

 



Copyright Statement

We encourage the reuse and dissemination of the material here for noncommercial purposes as long as attribution to the original material on the ACS site is retained. Material on this page is offered under a Creative Commons Attribution 3.0 License unless otherwise noted.

  • Attribution required
  • Allows remix of content
  • Commercial use not allowed

 

About the Green Chemistry Module Project

The ACS Green Chemistry Instiute has partnered with chemistry instructors from over 45 institutions to develop green chemistry education resources for undergraduate students studying general and organic chemistry.