Reaction Enthalpies

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Kristen Kim 2K
Posts: 70
Joined: Fri Sep 28, 2018 12:16 am

Reaction Enthalpies

Postby Kristen Kim 2K » Fri Feb 08, 2019 8:13 pm

What is the general formula for solving for reaction enthalpies? I'm having a hard time solving for problems where it asks to "calculate the heat absorbed."

MaanasO 1A
Posts: 72
Joined: Fri Sep 28, 2018 12:26 am

Re: Reaction Enthalpies

Postby MaanasO 1A » Fri Feb 08, 2019 9:14 pm

Hi Kristen!

There are three different ways to calculate the enthalpy of the reaction. One is breaking down the reaction into steps (those steps will be given to you) and altering the heat output of each step based on scalar multiplication and flipping the reaction and then summing them up. The second is sum(enthalpies of formation of all products) - sum(enthalpies of formation of all reactants). The third is similar to the second method, except you would use bond enthalpies instead of the enthalpies of formation.

Hope that helps!

Alexa Tabakian 1A
Posts: 38
Joined: Fri Sep 28, 2018 12:20 am

Re: Reaction Enthalpies

Postby Alexa Tabakian 1A » Fri Feb 08, 2019 11:58 pm

I noticed the problems in the book have a distinct way they would prefer you to solve them. For example, to use the version where you break down the different reactions, the book gives you the equations. Hope this helps!


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