O=C(NCc1ccccc1)C1C(=O)N(Cc2ccccc2)C(=O)C1C1(O)CCCC1
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?