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Bond Enthalpy

Posted: Sat Jan 25, 2020 4:05 pm
by Sofia Ban
What is bond enthalpy and why is it always a positive value?

Re: Bond Enthalpy

Posted: Sat Jan 25, 2020 4:21 pm
by Dina Marchenko 2J
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.

Re: Bond Enthalpy

Posted: Sat Jan 25, 2020 4:38 pm
by cassidysong 1K
^^ bond enthalpy is always positive because by definition the energy is always being put in.

Re: Bond Enthalpy

Posted: Sat Jan 25, 2020 5:02 pm
by Jasmine Vallarta 2L
requires energy > 0
releases energy < 0

Re: Bond Enthalpy

Posted: Sat Jan 25, 2020 10:31 pm
by DLee_1L
Another way to look at it is that Endothermic reactions require heat so + energy/heat and Exothermic reactions give off heat so energy/heat.