Bond Enthalpies

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Giselle Littleton 1F
Posts: 78
Joined: Wed Sep 18, 2019 12:20 am

Bond Enthalpies

Postby Giselle Littleton 1F » Thu Feb 06, 2020 2:14 am

I notice that in some problems from the homework, specific bonds within molecules aren't included when calculating the bond enthalpies. Why is that and how can I watch out for those that I should not include?

sarahsalama2E
Posts: 164
Joined: Fri Aug 30, 2019 12:16 am

Re: Bond Enthalpies

Postby sarahsalama2E » Thu Feb 06, 2020 2:51 pm

I'm not sure if this is exactly what you are referring to but molecules in their most stable state, aka H2, 02 do not have bond enthalpies because they are in their most stable state, because it takes no energy to form a naturally-occuring compound that wants to be formed.

Shrayes Raman
Posts: 129
Joined: Sat Jul 20, 2019 12:15 am

Re: Bond Enthalpies

Postby Shrayes Raman » Fri Feb 07, 2020 12:25 am

I may be misunderstanding your question however you do not need to include bond enthalpies for bonds that are not broken in a reaction, ie 3C2H2 -> C6H6 do not need H - C bond enthalpies because they are not broken

Maika Ngoie 1B
Posts: 97
Joined: Fri Aug 02, 2019 12:16 am

Re: Bond Enthalpies

Postby Maika Ngoie 1B » Sat Feb 08, 2020 4:41 pm

Normally bond enthalpies should be stated, unless it is the most stable form of the naturally occurring element, in which case it does not have a bond enthalpy.

Micah3J
Posts: 100
Joined: Tue Oct 08, 2019 12:16 am

Re: Bond Enthalpies

Postby Micah3J » Sat Feb 08, 2020 5:27 pm

If on a test we were asked to use Hess's law, we would be given a table that shows the bond enthalpies right? If anything I just need to remember which ones are 0.


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