Answer
The hydrogen on the right is more acidic.
Work Step by Step
If we remove the left proton, the conjugate base will have these changes:
- The Hydrogen on the left will be removed.
- The Oxygen that was connected to the Hydrogen will get a negative charge, because the electrons that were making the bond will turn into a lone pair.
If we remove the proton on the right, the conjugate base will have these changes:
- The Hydrogen on the right will be removed.
- The Oxygen that was connected to the hydrogen will get a negative charge, because the electrons that were making the bond will turn into a lone pair.
- But, since there is a pi bond next to the lone pairs of the oxygen, there will be a resonance structure, and the charge will be spread between the two oxygens.
Since the charge on the second conjugate base will be more delocalized, it will be more stable.
If the second conjugate base is more stable, the proton on the right is more acidic.
