Strength of Acids

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Letty Liu 2C
Posts: 105
Joined: Fri Aug 09, 2019 12:16 am

Strength of Acids

Postby Letty Liu 2C » Thu Dec 05, 2019 12:17 pm

Can somebody explain the properties that make an acid strong? I understand that longer, weaker bonds are stronger acids, but this concept is flipped when considering electronegativity. How would we know when to use which property?

AArmellini_1I
Posts: 107
Joined: Fri Aug 09, 2019 12:15 am

Re: Strength of Acids

Postby AArmellini_1I » Thu Dec 05, 2019 12:21 pm

For Binary acids:
Across a period: more polar the HA bond the stronger the acid (weak bonds)
Down a group: the weaker the HA bond the stronger the acid (so greater atomic diameter means a weak bond which means a stronger acid)
For OxoAcids:
The more O bonded to the central atom the stronger the acid
When # of O bonded to the central atom are the same look at the EN of the rest of the atoms

Parker Smith
Posts: 102
Joined: Thu Jul 25, 2019 12:15 am

Re: Strength of Acids

Postby Parker Smith » Thu Dec 05, 2019 12:24 pm

Electronegativity comes into play when comparing acids along a period and/or for polyatomic acids. For instance, HClO3 is stronger than HClO2 because the combine electronegativities of the oxygens in ClO3 create a more polar dipole, making the proton easier to remove. Bond length is for comparing same group acids like HCl and HBr. Her is stronger since it has a longer bond length between its proton, making it easier to remove than the proton on the smaller Cl ion.


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