Cc1ccc(/N=N/c2c(O)ccc3cc(S(=O)(=O)[O-])ccc23)c(C)c1.[Na+]
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?