Cc1c(Cl)cccc1-n1ncc(C(=O)Nc2ccc(Br)cc2F)c1C1CCNCC1
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?