O=C(NCc1ccc2c(c1)OCO2)C(C(=O)c1ccccc1)n1cc(Cl)ccc1=O
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?