O=C(Nc1cc(S(=O)(=O)N2CCOCC2)ccc1O)c1ccc2c(c1)S(=O)(=O)c1ccccc1C2=O
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?