A phase diagram shows the conditions needed for different phases of matter to exist in equilibrium. It indicates that applying enough pressure to ice will cause it to melt into liquid water, as seen by the red line. The triple point of a substance is the unique temperature and pressure where its solid, liquid, and gas phases coexist. For water, this is 0.01°C and 0.006 atm.

1. Phase Diagrams
A phase diagram shows the conditions at which the
distinct phases of matter can occur at equilibrium.

2. Phase Diagram
Melting
Freezing Vaporization
Condensation
Deposition
Sublimation

3. Phase Diagrams
Triple Point
The triple point of a
substance is the
Liquid temperature and
pressure at which
Solid
gas, liquid, and solid
coexist in
Gas
thermodynamic
equilibrium.

4. Phase Diagrams
Triple Point
For water, the
combination of
Liquid pressure and
temperature are
Solid
exactly 0.010000 C
and 0.0060373 atm.
Gas
At that point, the
liquid can boil and
freeze at the same
time.

5. Phase Diagram
According to the red line on the phase diagram,
if we apply enough pressure to ice, it will melt into liquid water.
What are the practical
applications?

6. Phase Diagram
According to the red line on the phase diagram,
if we apply enough pressure to ice, it will melt into liquid water.
Ice Skating is one application
of this phenomenon.

7. Phase Diagrams
Carbon dioxide
Dry Ice

8. Phase Diagrams
Carbon dioxide has
a vapor pressure of
830 psi (56.5 atm)
at 20 C.
Dry Ice
At 0 C the pressure inside a CO2 fire extinguisher is
about 500 psi. At 30 C it is about 1000 psi.

9. Phase Diagrams
Carbon