O=C(O)c1[nH]c2ccccc2c1C(c1cccc(O)c1)c1c(C(=O)O)[nH]c2ccccc12
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 pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?