Cc1ccc(S(=O)(=O)O)cc1.N/C(=N\O)N/N=C\c1ccc(O)c(O)c1O
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?