An experiment in chemical kinetics as part of our Discovery Chemistry curriculum is described. Discovery Chemistry is a pedagogical philosophy that makes the laboratory the key center of learning for students in their first two years of undergraduate instruction. Questions are posed in the pre-laboratory discussion and assessed using pooled student data. Results of experiments are then used in lecture to discover chemical principles. This experiment introduces students to integrated rate laws, the search for a mechanism that is consistent with chemical and kinetic data, and the concept of activation barriers and their measurement. (Contains 2 figures, 1 table, 1 scheme, and 5 notes.)