O=C(O)[C@]12C[C@]3(C(=O)O)C[C@@](C(=O)O)(C[C@](C(=O)O)(C1)C3=O)C2=O
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?