O=C(C[n+]1ccccc1)Nc1cc(C(F)(F)F)ccc1Cl.[Cl-]
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?