12B on Pizza Rolls Review Packet

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12B on Pizza Rolls Review Packet

Postby Jeremy_Guiman2E » Sun Feb 09, 2020 7:39 pm

12B) Suppose a researcher finds that delta H(rxn)=-2756 kJ for the reaction at 200. degrees C. Assuming all heat capacities are constant, calculate delta H(rxn) at the temperature of the human body, 37 degrees C. Hint: since enthalpy is a state function, the process can be divided into three steps.

Can someone explain why, for the "three steps", the reaction goes from 37 degrees to 200 degrees and then back down to 37? And/or how this is possible?

Deepika Reddy 1A
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Joined: Thu Jul 11, 2019 12:15 am

Re: 12B on Pizza Rolls Review Packet

Postby Deepika Reddy 1A » Sun Feb 09, 2020 7:43 pm

Enthalpy is a state function which means that only the initial and final enthalpy values matter. The pathway taken does not matter. Therefore, because we know the enthalpy for the reaction at 200 degrees C, we make the pathway in a way where the initial and final would still be the same but it will include the reaction at 200 degrees C so we can calculate the final.

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