O=c1[nH]/c(=C/c2ccc(OCc3ccccc3)cn2)c(=O)[nH]/c1=C/c1ccc(Cl)cc1
The negative base-10 logarithmic of dissociation constant (pKa) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?