Cc1cc[n+](C2=C([N-]S(=O)(=O)c3cccs3)C(=O)c3ccccc3C2=O)cc1C
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?