O=C(NCc1ccc(Cl)cc1)c1ccc2c(c1)NC(=O)C(CS(=O)(=O)Cc1ccc(F)cc1Cl)N2
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?