NNC(=O)C(=O)N/N=C1\CCC(=O)CC1C(=O)CCC(=O)Nc1ccc(Cl)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?