resonance and acid strength

[Kylie McCauley 1D]

Hi,
what is the connection between resonance and acid strength?

[Sabina House 2A]

Something with more resonance would be a stronger acid because the electrons would be delocalized. Electron delocalization stabilizes molecules and therefore leads to a more stable conjugate base of an acid. If a molecule has more double bonds, there is resonance to delocalize electrons, so this molecule would be a stronger acid.

[Steph Du 1H]

To add onto the above, the resulting anion having resonance and thus being more stable is what makes the acid more likely to give off its proton (thus a stronger acid).

[Tae Pasawat 2A]

Just to clarify, resonance only matters when dealing with nonbinary acids like carboxylic acids and oxoacids!