Phase Diagrams

A map of solid, liquid and gas

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Lines are where two phases coexist; the triple point is where all three do.
• Lower pressure → lower boiling point.
• CO₂ has no liquid below 5.1 atm; water’s melting line leans backwards.

Steps

1. A map for a substance
2. Going up a mountain
3. Pressure cooker
4. Freeze-drying
5. Water’s backwards line
6. Liquid carbon dioxide