Cc1ccc(CNCC(=O)Nc2cccc(S(=O)(=O)NC3=NCCCCC3)c2)cc1.O=C(O)C(=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?