O=C1NC(=O)C(=Cc2cc(Cl)ccc2OCc2ccc(C(=O)O)cc2)C(=O)N1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?