Hess's Law

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Megan Purl 1E
Posts: 49
Joined: Fri Sep 29, 2017 7:07 am

Hess's Law

Postby Megan Purl 1E » Mon Jan 15, 2018 9:25 pm

What exactly is Hess's Law?

Ashley Garcia 2L
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Joined: Fri Sep 29, 2017 7:05 am

Re: Hess's Law

Postby Ashley Garcia 2L » Mon Jan 15, 2018 9:56 pm

Hess's law states that the overall reaction enthalpy change is the sum of all the reaction enthalpies, regardless of the multiple steps into which the reaction can be divided. We are able to add the reaction enthalpies because enthalpy is a state function, in which the overall reaction enthalpy change is independent of the path between the initial and final states.

Kelly Kiremidjian 1C
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Joined: Fri Sep 29, 2017 7:04 am

Re: Hess's Law

Postby Kelly Kiremidjian 1C » Tue Jan 16, 2018 11:41 am

Hess's law states that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states. This is useful for us in calculating change in enthalpy's because we can then use reactions with known enthalpy's and manipulate them to find the enthalpy of the desired reaction.

Tatiana Hage 2E
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Re: Hess's Law

Postby Tatiana Hage 2E » Tue Jan 16, 2018 11:58 am

Hess's Law states that the overall reaction enthalpy is the sum of the reaction enthalpies of the steps into which the reaction can be divided. To use Hess's Law to find the enthalpy of a given reaction, we find a sequence of reactions with known reaction enthalpies that adds up to the reaction of interest.


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