Calculating Standard Enthalpy of Reaction

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Christina_F_3F
Posts: 21
Joined: Fri Jul 22, 2016 3:00 am

Calculating Standard Enthalpy of Reaction

Postby Christina_F_3F » Sun Jan 15, 2017 1:18 pm

In class, we discussed how if there is a solid in a chemical reaction for which you are trying to find the standard enthalpy of reaction. you must consider the fact that there is both a phase change as well as an enthalpy change for that solid.
My question is, why does this apply to just solids? Might there also be phase changes that need to be accounted for for liquids and gases as well?

Paul_Ajodha_2K
Posts: 11
Joined: Fri Jul 22, 2016 3:00 am

Re: Calculating Standard Enthalpy of Reaction

Postby Paul_Ajodha_2K » Sun Jan 15, 2017 1:59 pm

When you're trying to find the changes in enthalpies between phase changes it does not only apply to solids. I believe that in the case you're talking about, they're only accounting for the phase change associated with solids, but if you were to be calculating change in enthalpy from a gas to a solid you would definitely have to account for the change in enthalpy for each phase change every step of the way and not just the phase change associated with that of solids. I hope this helps!


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