CCOc1ccc(S(=O)(=O)N2CCC(C(=O)Nc3cc(S(C)(=O)=O)ccc3Cl)CC2)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?