O=C(Nc1cc(F)ccc1F)c1cc2nc(-c3ccco3)cc(C(F)(F)Cl)n2n1
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?