Relative Acidity and stability

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Jonathan Batac - 2D
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Joined: Wed Sep 30, 2020 10:03 pm

Relative Acidity and stability

Postby Jonathan Batac - 2D » Fri Dec 04, 2020 12:04 pm

Can someone explain the significance of having a stable anion in order to have a strong acid? Why does it matter if it is stable or not?

dana hu 1B
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Re: Relative Acidity and stability

Postby dana hu 1B » Fri Dec 04, 2020 12:10 pm

hello!
The strength of an acid in an organic compound is proportional to the stability of the acid’s conjugate base. In other words, an acid that has a more stable conjugate base will be more acidic than an acid that has a less stable conjugate base.
It likes to have electrons around it and, therefore, it makes sense that anion is the best at stabilizing a negative charge and that makes this the most stable conjugate base. And if the anion is the most stable conjugate base, which means that the compound must be the strongest acid.

Chem_Mod
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Re: Relative Acidity and stability

Postby Chem_Mod » Fri Dec 04, 2020 12:11 pm

An acid is strong if it can easily give off a Hydrogen atom. If the anion that results from the loss of a Hydrogen atom is stable, that molecule is more likely to give off a Hydrogen atom.

Jiapeng Han 1C
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Re: Relative Acidity and stability

Postby Jiapeng Han 1C » Fri Dec 04, 2020 10:32 pm

Higher stability means a species is more easily to be formed. If the resulting anion isn't stable enough, then the dissociation won't be complete, which means that the acid is by definition, weak. The same logic applies to base as well.

Alexandra Salata 2L
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Re: Relative Acidity and stability

Postby Alexandra Salata 2L » Fri Dec 04, 2020 11:48 pm

Anion stability is about the anion product of acid dissociation. If the anion is not stable, it will recombine with H+ and the reverse reaction dominates so there is less dissociation (higher pH). The more stable the anion, the more dissociation "remains" (less reverse reaction and so on).


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