CCOc1cc(C2c3c(oc4ccccc4c3=O)C(=O)N2Cc2ccc3c(c2)OCO3)ccc1O
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?