The Phase Diagram Tutorial is an interactive animation where students "create" a virtual phase diagram. Then, they identify the six processes that occur at the phase boundaries and construct the heating curve of water (ice to steam) on top of the phase diagram. This tutorial like all Chem21Labs' tutorials provides a safe environment for learning . . . . students receive "full credit" when they complete the tutorial correctly - it does not matter how many times they miss part of it and have to start over. This animation is typically a lecture assignment, but can be assigned as a post-lab activity (i.e. Heat of Fusion lab) . . . . assigning the same interactive tutorial in lecture and lab is a great way to "connect" the learning between the two classes.
- Students learn how pressure and temperature affect the states of matter.
- Students "create" a virtual phase diagram by dragging/dropping dots along the solid/gas phase, the solid/liquid phase, and the liquid/gas phase. The placement of the triple point dot and critical point dot complete the phase diagram.
- Students identify the six processes that occur when solid ⇌ liquid (melting, freezing), liquid ⇌ gas (vaporization, condensation), and solid ⇌ gas (sublimation, deposition).
- Students add "50 J packets" of energy to virtually warm ice to 0°C, melt the ice at 0°C, warm the 0°C water to 100°C, vaporize the water to steam at 100°C, and warm the steam. Students quickly realize that the liquid to gas phase change (Heat of Vaporization) requires much more heat (more clicking of the 50 J icon) than the solid to liquid phase change (Heat of Fusion).
- At the end of the animation is a calculation where students are randomly assigned a mass of ice or water, a starting temperature and an ending temperature. They use this information to calculate the energy needed to warm the water from its starting temperature to its ending temperature.
- If the student miscalculates this energy, they are shown the step-by-step solution . . . however, they must restart the animation.
- Students receive "full credit" when they complete the animation correctly - it does not matter how many times they must restart it.
- The HTML5-JS version is shown below.