Oxoacid Strength

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ayushibanerjee06
Posts: 130
Joined: Thu Jul 11, 2019 12:16 am

Oxoacid Strength

Postby ayushibanerjee06 » Sat Dec 07, 2019 7:27 pm

Would HOF or HOCl be a stronger acid? Since oxoacid strength is based on electronegativity, shouldn't HOF be stronger than HOCl?

Alex Tchekanov Dis 2k
Posts: 98
Joined: Sat Aug 24, 2019 12:16 am

Re: Oxoacid Strength

Postby Alex Tchekanov Dis 2k » Sat Dec 07, 2019 7:35 pm

The HOCl bond is longer than the HOF bond. Therefore, since the stability and thus electronegativity doesn't matter, it is the length of the bond that does.

Sebastian Lee 1L
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Re: Oxoacid Strength

Postby Sebastian Lee 1L » Sat Dec 07, 2019 7:36 pm

Yep, HOF is the stronger acid! When the acids dissociate and donate their proton, you will be left with the anions, FO- and ClO-. Since F is more electronegative it will be able to better delocalize the negative charge of the Oxygen by pulling the electrons closer to it. This delocalization/induction makes the anion more stable. Since the FO- anion is more stable HOF is more likely to stay dissociated and is therefore the stronger acid.

Remember that, in this case, bond length DOES NOT MATTER because both have OH bonds. The bond with the hydrogen is the SAME LENGTH in both of them.

Abigail_Hagen2G
Posts: 85
Joined: Fri Aug 09, 2019 12:17 am

Re: Oxoacid Strength

Postby Abigail_Hagen2G » Sat Dec 07, 2019 10:38 pm

Okay, that makes sense. So, when concerning bond lengths, it's the comparison between hydrogen and another atom.

Matt F
Posts: 80
Joined: Sat Aug 17, 2019 12:17 am

Re: Oxoacid Strength

Postby Matt F » Sat Dec 07, 2019 11:00 pm

^Correct. Strength for oxoacids is based on the stability of the resulting anion, which is influenced by electronegativity (withdraws electron density) and resonance. Typically I would just look at which acid contains the more electronegative atom

Annie Ye
Posts: 106
Joined: Wed Sep 18, 2019 12:22 am

Re: Oxoacid Strength

Postby Annie Ye » Sun Dec 08, 2019 6:36 pm

You would only look at bond lengths if it was with binary acids. For oxoacids, you would look at the electronegativity.

jisulee1C
Posts: 94
Joined: Thu Jul 25, 2019 12:17 am

Re: Oxoacid Strength

Postby jisulee1C » Sun Dec 08, 2019 6:36 pm

HOCl would act as the stronger acid.


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