Fig. 4.2 shows a typical example of a 3D phase diagram of a pure substance.
The projection from the front represents the 2D \(p-V\) diagram. The projection from the right side represents the 2D \(p-T\) diagram.
Areas marked with (1) are regimes with one phase; areas marked with (2) are regimes with two phases.
The line from A to F represents a path with constant pressure, i.e. an isobaric (e.g. open container) heating experiment of a non-anomalous substance. The substance cannot be water since in this case one would expect a decrease in volume when melting occurs (anomaly of water based on its expanded solid structure).
A\(\rightarrow\)B: pure solid, small increase of \(V\).
B\(\rightarrow\)C: solid + liquid, strong increase of \(V\), isothermal due to latent heat.
C\(\rightarrow\)D: pure liquid, small increase of \(V\).
D\(\rightarrow\)E: liquid + gas, strong increase of \(V\), isothermal due to latent heat.
E\(\rightarrow\)F: pure gas, moderate increase of \(V\).
Triple line: coexistence of three phases.
L\(\rightarrow\)M: no phase segregation due to supercritical fluid (SCF).
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© J. Carstensen (TD Kin I)
