1. Chapter 4 Revision

2. Checklist of Key Ideas
A phase is a form of matter that is uniform throughout in chemical composition and physical state.
A transition temperature is the temperature at which two phases are in equilibrium.
A phase diagram is a diagram showing the regions of pressure and temperature at which various phases are thermodynamically stable.
A phase boundary is a line separating the regions in a phase diagram showing the values of pressure and temperature at which two phases coexist in equilibrium.

3. Checklist of Key Ideas
The vapor pressure is the pressure of a vapor n equilibrium with the condensed phase.
The boiling temperature is the temperature at which the vapor pressure of a liquid is equal to the external pressure.
The critical temperature is the temperature at which a liquid surface disappears and above which a liquid does not exist whatever the pressure.
The melting temperature is the temperature at which, under a specified pressure, the liquid and solid phases of a substance coexist in equilibrium.

4. Checklist of Key Ideas
The triple point is a point on a phase diagram at which the three phase boundaries meet and three phases are in mutual equilibrium.
The chemical potential m of a pure substance is the molar Gibbs energy of the substance.
The chemical potential is uniform throughout a system at equilibrium.

5. Checklist of Key Ideas

6. Checklist of Key Ideas

7. Checklist of Key Ideas