Solving bond enthalpies

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305174946
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

Solving bond enthalpies

Postby 305174946 » Fri Jan 25, 2019 11:46 am

Why is it reactants minus products when solving for the enthalpy of the reaction using bond enthalpies?

michelle
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

Re: Solving bond enthalpies

Postby michelle » Fri Jan 25, 2019 4:01 pm

Breaking bonds requires energy, resulting in positive enthalpy while forming bonds release energy, resulting in negative enthalpy. In other words, the enthalpy change made by reactants is positive while that made by forming products is negative.

Michael Novelo 4G
Posts: 64
Joined: Fri Sep 28, 2018 12:28 am

Re: Solving bond enthalpies

Postby Michael Novelo 4G » Fri Jan 25, 2019 4:22 pm

In addition to what has previously been stated if the Reactants - Products equals a negative value then the reaction is exothermic and if it is positive it is endothermic.

Katelyn Phan 2A
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

Re: Solving bond enthalpies

Postby Katelyn Phan 2A » Fri Jan 25, 2019 6:52 pm

When you break a bond, you require energy. (+) On the other hand, when a bond is formed, energy is released. (-)


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