Phase Changes
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Phase Changes
For reactions where substances are not in their most stable/standard phase, how would you account for that when calculating enthalpies?
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Re: Phase Changes
If the substance is not in the most stable/standard phases then you must use the total of the enthalpy of the phase change and the bond enthalpy when calculating.
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Re: Phase Changes
When the substance is not in its standard state at the given temperature, you have to add the enthalpy of its phase changes. For example if its a gas in its standard state and is currently a solid, you would have to add the enthalpy of its sublimation.
Re: Phase Changes
Yes, as the previous response said, you must add the enthalpy of the phase change.
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Re: Phase Changes
The proper method is to calculate the enthalpy, then add the enthalpy of the phase change.
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Re: Phase Changes
To accommodate for the phase change of the material, add the reaction enthalpy of the phase change onto the reaction.
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