CCOc1cc(/C=C(\C#N)C(=O)Nc2ccc(S(N)(=O)=O)cc2)ccc1OCCN1CCOCC1
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?