COc1ccc(Cl)cc1NS(=O)(=O)c1cccc(C(=O)NCC(c2ccco2)N(C)C)c1
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?