Phase Change Diagrams: Slopes

[MSkye Goldwater 2K]

When drawing the phase change diagram for a given substance, how do we determine the steepness of the gas, liquid, and solid phases? Also, how do you know which line you draw longer, the heat of vaporization or the heat of fusion?

[Sophie Krylova 2J]

Heat of vaporization line os longer, because heat required for the process is represented by the x axis and vaporization requires more heat than fusion (the bonds between the molecules are completely broken). I believe the steepness is determined by the specific enthalpy values, but I am not 100% sure..

[Anna Okabe]

The slope of the heating curve is the heat capacity of each phase. For example, the slope of the line of fusion (between ice and water) is the heat capacity of solid water).