Enthalpy diagram help

Question

Frost forms on the windshield of a car on a cold winter morning. This frost disappears with no evidence that water forms.

Draw an enthalpy diagram to illustrate the change. (If possible please make a video showing me how to draw it please)

Answer 1

The enthalpy diagram has enthalpy as the y-axis (as you ascend, the enthalpy rises) and the time sequence is on the x-axis. It's not exactly important where you start the scale for the enthalpy axis; technically, it should start for ice at absolute zero -- but the important stuff is how large are the steps when you have a phase transition. I think I clued you in on how large those were, your last entry on this -- sublimation of water = +540+80=+620 cal/g

-- Cheers, --Mr. d.