O=C(CSc1ncc2c(n1)-c1ccc(Cl)cc1N(Cc1ccccc1)S2(=O)=O)Nc1ccc(F)c(F)c1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?