Cl.O=C(NCC(c1cccs1)N1CCOCC1)c1ccccc1NS(=O)(=O)c1ccc(Cl)c([N+](=O)[O-])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?