pka_value	data_source	charge_state_pre	charge_state_post	microspecies_pre	microspecies_post	molid	smiles
1.57	IUPAC digitized pKa	0	-1	O=C(O)C(O)=C(O)C(=O)O	O=C([O-])C(O)=C(O)C(=O)O	mol9124	O=C(O)C(O)=C(O)C(=O)O
1.13999998569489	QSARToolbox	0	-1	O=C(O)C(O)=C(O)C(=O)O	O=C([O-])C(O)=C(O)C(=O)O	mol9124	O=C(O)C(O)=C(O)C(=O)O
3.36	IUPAC digitized pKa	-1	-2	O=C([O-])C(O)=C(O)C(=O)O	O=C([O-])C(O)=C(O)C(=O)[O-]	mol9124	O=C(O)C(O)=C(O)C(=O)O