O=C(Nc1ccc(S(=O)(=O)Nc2nccs2)cc1)C1CC(=O)N(c2ccc(Cl)cc2)C1
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?