How the kinetics of E1cb is 2nd order?

The E1cb (unimolecular elimination via a conjugate base) mechanism is considered second-order because it involves two distinct steps: the formation of a conjugate base and the subsequent elimination of a leaving group. The rate-determining step involves both the deprotonation of the substrate and the loss of the leaving group, making it dependent on the concentrations of both the substrate and the base. Consequently, the overall rate law reflects this dependence, resulting in a second-order reaction.