Segments A, C, and E represent energy transfer from the heating source (heat) resulting in the increase in temperature of each particular state. Segments B and D represent heat transfer which is consumed by a change of state.

Segment A represents the heat absorbed by ice providing an increase in temperature. The Specific Heat Capacity of Ice is 36.57 J/mole▪oC.

= warming of iceq=nCiceΔt; Cice= 36.57 J/mole▪oC

Segment B represents the equilibrium between the solid phase of water (ice) and the liquid phase. The energy associated with this phase change is defined as the Molar Heat of Fusion (ΔHfusion). ΔHfusion equals 6.009 kJ/mole. The temperature of this segment defines the melting point of ice.

= phase change slq=nΔHfus; ΔHfus= 6.009 kJ/mole

Segment C exhibits the heat absorbed by liquid water resulting in a temperature increase. The Specific Heat Capacity of Water is 75.4 J/mole▪oC.

= warming of liquid waterq=nCliquidΔt; Cliquid= 75.4 J/mole▪oC

Segment D defines the equilibrium between the liquid and gas phase of water. The energy associated with this phase change is defined as the Molar Heat of Vaporization (ΔHvap). ΔHvap equals 40.66 kJ/mole. The temperature of this segment defines the boiling point of water.

= phase change lg q=nΔHvap; ΔHvap= 40.66 kJ/mole

Segment E represents the heat absorbed by water vapor providing an increase in temperature. The Specific Heat Capacity of Water Vapor is 34.26 J/mole▪oC.

warming of water vapor =q=nCvapΔt; Cvap= 34.26 J/mole▪oC