Chapter 4 Revision

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.

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.

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.

Checklist of Key Ideas

Checklist of Key Ideas

Checklist of Key Ideas