O=C(O)CCC/C=C\C[C@H]1[C@@H](O)C[C@H](F)[C@@H]1/C=C/[C@H](O)C1Cc2ccccc2C1
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?