Question

what is the relationship between pressure and temp. on a phase diagram? why is this different than a heating curve?

Answer 1

Phase diagrams illustrate the variations between the states of matter of elements or compounds as they relate to pressure and temperatures.

A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature, and also provide the pressure dependence of the phase-transition temperatures like melting points, sublimation points, boiling points.

Heating curve:

At some point of phase diagram, when the temperature increased at constant pressure then we obtain heating curve.And the graph is Temperature vs time at constant pressure.