Calculating a Simple Phase Diagram: Diamond=Graphite
This is a very short exercise designed to get students to understand how the Gibbs energy equation is used to calculate the location of a reaction in P-T space. I use it in-class and have students work on it in groups.
Context
Audience: This exercise is used in a sophomore or junior level required course in petrology.
Skills and concepts that students must have mastered: Students should have an understanding of Gibbs energy.
How the activity is situated in the course: This activity is a stand-alone exercise.
Goals
Content/concepts goals for this activity: This exercise is designed to get students to understand how the Gibbs energy equation is used to calculate the location of a reaction in P-T space.
Higher order thinking skills goals for this activity:
Other skills goals for this activity: This activity may involve group work.
Description of the activity/assignment
This is a very short exercise designed to get students to understand how the Gibbs energy equation is used to calculate the location of a reaction in P-T space. I use it in-class and have students work on it in groups.
Besides calculating the location of one reactions, students also have to think a bit about the significance of volume and entropy with regard to mineral stability.
This exercise is very straightforward EXCEPT that students get the units (bars, Kbar, cc, etc.) confused.
Determining whether students have met the goals
Students have met the goals of this assignment if they are able to complete the exercise accurately and completely.
More information about assessment tools and techniques.Download teaching materials and tips
- Activity Description/Assignment (Acrobat (PDF) 31kB Sep29 03)
- Solution Set (Acrobat (PDF) 35kB Sep29 03)
Other Materials
Supporting references/URLs
