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Acid Strength

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nemzy:
Why is HSO3- a stronger acid then H2SO3?

And also, i know that When the size of an atom X increases, the H-X bonds decreases, meaning the strength of the acid increases since more H+ are ionized.

But when when H-X are more electronegitive, doesnt it mean the bonds between the H-X gets stronger, meaning fewer H+ ionizes?? But this is not the case, the more electrongetive the bond between H-X, the acid strength gets stronger. Is my conceptual idea wrong?

Also, lets say you have solutions of NH3, HCl, NaOH, and HC2H3O2 , all with the same solute concetrations. How would you know rank the pH of these solutions from highest to lowest or vice versa?

AWK:
HSO3- is weaker (not stronger) acid than H2SO3
K1H2SO3=1.7.10-2, K2H2SO3=6.2.10-8


TRUE


NOT TRUE: HF is a weak acid,
H2S is the weakest acid, H2Se - medium, H2Te the strongest one in this serie.

HCl, CH3COOH, NH3, NaOH - the first one is the most acidic substance, the last one  - most basic

Username:
So how exactly can you conclude from the structure of the acid to its strength if not by looking at the electronegativity of the atoms?
How about looking at the stability of the product - the corresponding base?

Mitch:
electronegativity is negligeable when compared to the polarizability of the molecule, in general. HI is more polarizable than HF.

Username:
Thanks for the response.
I just had a look at google about polarizability and it looks like a pretty complex subject since the polarizability of molecules is linked to its environment and stuff.
Looks like I'm gonna need some freetime to understand this one ;)

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