C[C@]12CCC3C(CC[C@H]4CC(OS(=O)(=O)[O-])CC[C@@]34C)C1CCC2=O.[Na+]
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?