O/N=C1C(=C\c2ccc3c(c2)OCCO3)\CCCC\1C(NO)c1ccc2c(c1)OCCO2
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?