CCC(Sc1ncc(S(=O)(=O)c2ccc(Cl)cc2)c(=O)[nH]1)C(=O)Nc1ccc(OC)cc1
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?