Autoprotolysis of water endo or exo?

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Ryan Narisma 4G
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Joined: Fri Aug 30, 2019 12:18 am

Autoprotolysis of water endo or exo?

Postby Ryan Narisma 4G » Mon Jan 13, 2020 11:29 am

Is the autoprotolysis of water an endothermic reaction or exothermic? The reaction forms an OH bond and is breaking an OH bond so is the change in enthalpy 0?

Mitchell Koss 4G
Posts: 128
Joined: Sat Jul 20, 2019 12:17 am

Re: Autoprotolysis of water endo or exo?

Postby Mitchell Koss 4G » Mon Jan 13, 2020 11:33 am

The autoionization of water is an endothermic reaction.

Eileen Si 1G
Posts: 120
Joined: Fri Aug 30, 2019 12:17 am

Re: Autoprotolysis of water endo or exo?

Postby Eileen Si 1G » Mon Jan 13, 2020 5:04 pm

Adding onto what the previous person said, because the autoionization of water is an endothermic reaction, the change in enthalpy is positive, because endothermic reactions require heat, which causes the products to be more favored than the reactants.

EMurphy_2L
Posts: 128
Joined: Sat Sep 07, 2019 12:16 am

Re: Autoprotolysis of water endo or exo?

Postby EMurphy_2L » Mon Jan 13, 2020 5:06 pm

can someone elaborate on why this is endothermic? because a bond is both being formed and broken (exo and endo, respectively)...

Tiffany_Chen 2K
Posts: 106
Joined: Fri Aug 30, 2019 12:15 am

Re: Autoprotolysis of water endo or exo?

Postby Tiffany_Chen 2K » Mon Jan 13, 2020 5:12 pm

If you think of the reverse reaction (2H2+O2->2H2O), energy is released to form the covalent bonds of water. Thus the reverse is exothermic, while the forward reaction (protonation of H2O) is endothermic.


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