Bond Enthalpy

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Sofia Ban
Posts: 80
Joined: Fri Sep 28, 2018 12:25 am

Bond Enthalpy

Postby Sofia Ban » Sat Jan 25, 2020 4:05 pm

What is bond enthalpy and why is it always a positive value?

Dina Marchenko 2J
Posts: 54
Joined: Thu Jul 25, 2019 12:16 am

Re: Bond Enthalpy

Postby Dina Marchenko 2J » Sat Jan 25, 2020 4:21 pm

Bond Enthalpy is the enthalpy (essentially the energy) needed to break a bond. All bonds require an input of energy in order to be broken (see bond potential energy graph) and a positive enthalpy signifies that energy must be put in. This is why all bond enthalpies are positive. The bond enthalpy of H2 is the energy required to break the covalent bond between the 2 H atoms.

cassidysong 1K
Posts: 100
Joined: Fri Aug 30, 2019 12:15 am

Re: Bond Enthalpy

Postby cassidysong 1K » Sat Jan 25, 2020 4:38 pm

^^ bond enthalpy is always positive because by definition the energy is always being put in.

Jasmine Vallarta 2L
Posts: 102
Joined: Sat Aug 17, 2019 12:18 am

Re: Bond Enthalpy

Postby Jasmine Vallarta 2L » Sat Jan 25, 2020 5:02 pm

requires energy > 0
releases energy < 0

Posts: 103
Joined: Sat Aug 17, 2019 12:17 am

Re: Bond Enthalpy

Postby DLee_1L » Sat Jan 25, 2020 10:31 pm

Another way to look at it is that Endothermic reactions require heat so + energy/heat and Exothermic reactions give off heat so energy/heat.

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