For the molecule HOCOO-, does the oxygen in the OH group participate in resonance? Is that particular contributing structure a major contributor to the hybrid structure? After a bit of discussion with peers, we agree the oxygen has electron-withdrawign effects, but since it is already bonded to a hydrogen, adding electrons to the oxygen would disrupt its current bond (i.e. too many electrons would destabilize the atom). Is there any support for the oxygen in the OH either participating or not participating in resonance? If so, do you mind providing an explanation? Thank you!