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Chemistry Forums for Students => High School Chemistry Forum => Chemistry Olympiad and other competitions => Topic started by: Loael on March 18, 2013, 11:41:55 PM

Title: Please help me understand fusion.
Post by: Loael on March 18, 2013, 11:41:55 PM
Okay, so I'm trying to study for the Olympiad and these two questions appeared:

Which process is exothermic?
A) Condensation
B) Fusion
C) Sublimation
D) Vaporization

The answer to this was A, so I assumed that fusion is an endothermic process.

Then this question comes up:

Rank the enthalpies of fusion, sublimation, an vaporization for water.

A) sublimation=vaporization=fusion
B) vaporization < sublimation < fusion
C) fusion < sublimation < vaporization
D) fusion < vaporization < sublimation

The answer to this was D.
This question really bothered me because shouldn't fusion have the HIGHER enthalpy value because it is endothermic? Please help me with this concept.
Title: Re: Please help me understand fusion.
Post by: Sunil Simha on March 24, 2013, 08:37:42 AM
Fusion is the process of conversion of a solid to a liquid. It is endothermic but the energy required for this phase change is usually lesser than that required for converting a liquid into a gas i.e. vaporization.