👉 Aujeszky's law, also known as the "J" rule, is a mathematical principle in molecular chemistry that describes the stability and thermodynamic properties of nucleophilic reactions between two molecules. According to this law, the more electronegative the first molecule (the donor) is, the easier it is for the second molecule (the acceptor) to donate electrons to stabilize its protonation state, which can then lead to a stronger than usual reaction rate.