N#Cc1c(-c2ccc(Cl)c(Cl)c2)c(-c2ccc(Cl)c(Cl)c2)nn(CC(=O)O)c1=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?