A study of the reaction [Fe(CN)(5)(4-CNpy)](3-) + CN-reversible arrow Fe(CN)(6)(4-) + 4-CNpy was carried out in hexadecyltrimethylammonium chloride (CTACl) micellar solutions. We conclude that the well-known pseudophase model, an extension of the Olson-Simonson treatment to micellar solutions, is equivalent to the Bronsted equation in regard to the interpretation of the micellar effects on reactivity. The equivalence follows from the fact that both pseudophase and Bronsted approaches can be used to rationalize kinetic data, as well as from thermodynamic considerations.