COc1c(C)c2c(c(C)c1Cl)Oc1c(C=O)c(O)c(Cl)c(C)c1C(=O)O2
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?