Hess' Law

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Ryan Yoon 1L
Posts: 55
Joined: Mon Jul 01, 2019 12:15 am

Hess' Law

Postby Ryan Yoon 1L » Fri Jan 31, 2020 10:32 am

Why can we add or subtract enthalpy changes?

Connie Chen 1E
Posts: 51
Joined: Mon Jun 17, 2019 7:24 am

Re: Hess' Law

Postby Connie Chen 1E » Fri Jan 31, 2020 10:35 am

Enthalpy is a state property, meaning that it is not dependent on the path taken to obtain that state, and state properties can be added or subtracted.

Zoe Gleason 4F
Posts: 51
Joined: Tue Jul 23, 2019 12:15 am

Re: Hess' Law

Postby Zoe Gleason 4F » Fri Jan 31, 2020 11:01 am

Since it is a state property, only the final and initial state will matter. This allows us to add and subtract the values of enthalpy.

Ellen Amico 2L
Posts: 101
Joined: Thu Sep 19, 2019 12:16 am

Re: Hess' Law

Postby Ellen Amico 2L » Fri Jan 31, 2020 11:51 am

Yes! Because enthalpy is a state property, we can add or subtract the enthalpy changes in order to get to an overall reaction since the path we take to get there doesn't matter.

705121606
Posts: 68
Joined: Wed Sep 18, 2019 12:17 am

Re: Hess' Law

Postby 705121606 » Fri Jan 31, 2020 3:53 pm

yes! this is because it is a state property

Ashley Alvarado 2C
Posts: 45
Joined: Sat Aug 17, 2019 12:16 am

Re: Hess' Law

Postby Ashley Alvarado 2C » Fri Jan 31, 2020 4:26 pm

Enthalpy changes can be added and subtracted because enthalpy is a state property.

Leslie Almaraz 4G
Posts: 99
Joined: Fri Aug 02, 2019 12:16 am

Re: Hess' Law

Postby Leslie Almaraz 4G » Fri Jan 31, 2020 6:03 pm

State properties are allowed to be added or subtracted to each other.

Orrin Zhong 4G
Posts: 51
Joined: Sat Jul 20, 2019 12:16 am

Re: Hess' Law

Postby Orrin Zhong 4G » Fri Jan 31, 2020 6:29 pm

Enthalpy is a state property, so only the final and initial states matter. The process by which you get from an initial state to a final state does not matter for state properties. Therefore, if you want to find the enthalpy value of a reaction through Hess' Law, you can just add the enthalpy values (ensuring that the intermediates cancel out).


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