Why is the heat of sublimation, ΔHsubl, equal to the sum of ΔHvap...

Question

Why is the heat of sublimation, ΔHsubl, equal to the sum of ΔHvap and ΔHfusion at the same temperature?

Accepted Answer

Hey everyone where asked which statement is correct regarding the heat of vaporization, heat of fusion and the heat of sublimation at the same temperature as we've learned. Sublimation is the direct conversion of a solid to a gas, and sublimation is very similar to melting, followed by vaporization. And since energy is a state function, the energy required to convert a solid to a gas must be the same regardless of the path. So looking at our answer choices, it looks like answer choice A fits our description. The heat of sublimation is equal to the sum of the heat of vaporization and the heat of fusion because sublimation is synonymous with melting, followed by vaporization and the energy of sublimation is path independent, which is essentially what we just stated Now. I hope that made sense and let us know if you have any questions.

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