At a Glance


  • STEM
  • Chemistry

Instructional Level

  • College & CEGEP
  • University


  • General Chemistry

Tasks in Workflow

Social Plane(s)

  • Individual
  • Group

Type of Tasks

  • Collecting & seeking information
  • Solving problems
  • Analyzing
  • Reviewing & assessing peers
  • Revising & improving
  • Writing

Technical Details

Useful Technologies

  • Whiteboards, interactive whiteboards
  • online collaborative platform


  • Single class period (< 90 mins)

Instructional Purpose

  • Application & knowledge building


In this activity, students are presented with a case study in which the challenge is to rescue six researchers that have been captured and exposed to a potentially deadly chemical reaction.

Working in groups, students will:

  • Determine what the reaction of interest is,
  • Employ stoichiometry to identify the limiting reagent in the reaction, and
  • Employ the ideal gas law to determine the volume of a toxic gas produced.

Once the rescue is completed, groups will prepare a generalized problem solving heuristic of the procedure that will be reviewed by their peers. Generation and peer editing of the heuristic’s flowchart is intended to support efforts to tackle such problems, and to identify underlying patterns and similarities between different problem types.

Instructional Objectives

To promote development of skills required to solve complex problems including the following: knowledge application, analysis and evaluation of solution.

To encourage the application of inductive reasoning (from a specific case study to generalized principles) to generate a problem solving heuristic.

Workflow & Materials


Activity Workflow

View on CourseFlow

Contributor's Notes

Yann Brouillette

Yann Brouillette

Dawson College, Montreal


Overall, carrying out this activity really helped my students grasp underlying concepts and the manner in which different components of the cirriculum can come together. When my Chemistry class was faced with a similar question on the midterm examination, students performed very well (even though it was the most complicated question on that particular test). Overall, average for that question was 87% (with 9/19 students getting full marks) versus 76% for the entire midterm.


The in-class portion of this activity will generally take up an entire 90-minute session. Thus, some planning is required to ensure that you set up sufficient time for the activity. However, the benefits of generating the problem-solving heuristic outweigh the time required (see comments in benefits).


Instructors must indicate from the start that problem solving heuristics should be generalizable and will be used to solve similar problems (i.e., the heuristics cannot be so detailed or specific as to solve only this particular case study). It is essential that students learn to recognize underlying patterns that appear in such problem types.

Instructors should keep track of time, and ensure no group gets completely stuck at any given step.

Instructors should attend to group composition, for instance I try to ensure that each group has 1-2 stronger students and emphasize that the activity is “GROUP” oriented. I look out for any individual trying to take control of the entire activity or students that do not seem to be participating.

Applied Strategies


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