Cc1onc(-c2c(Cl)cccc2Cl)c1C(=O)NCc1ccc(S(N)(=O)=O)cc1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?