O=C(O)C1C2C=CC3(O2)C1C(=O)N1c2ccccc2C2OCCC2C13
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?