How do highly electronegative atoms diffuse net charge?

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How do highly electronegative atoms diffuse net charge?

Postby Chem_Mod » Sun Aug 21, 2011 11:59 am

How do highly electronegative atoms in a polyatomic conjugate base (like trichloroacetate) create a "chain effect" that diffuses the net charge and makes it more stable? Is this why a higher oxidation number for the central atom of an oxoacid (e.g. HClO4) makes it a stronger acid when deprotonated?

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Re: How do highly electronegative atoms diffuse net charge?

Postby Chem_Mod » Sun Aug 21, 2011 12:00 pm

If you draw the Lewis structure for the conjugate base of HClO4 which is ClO4-. You will soon see that the anion is greatly stabilized by many resonance structures. Second, remember that O is more electronegative then Cl, so all O=Cl bonds would pull the electron densities away from the "-" charge, stabilizing the anion even more (which is similar to the case of trichloroacetate). That's why HClO4 is such a strong acid.


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