O=C(NCc1cc(C(F)(F)F)ccc1Cl)c1cccc2c1C(=O)c1ccc(N3CCC(N4CCCCC4)CC3)cc1S2(=O)=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?