$word_{count}$: 200

Four experimental methods to find order: (1) Initial rates method (most direct): run multiple experiments varying one concentration at a time. Order w.r.t. A: m = log$\frac{rate2/rate1}{log}$([A]2/[A]1). If doubling [A] doubles rate: m=1. Quadruples: m=2. No change: m=0. (2) Integrated rate law method: plot [A] vs t, ln[A] vs t, and 1/[A] vs t. The linear plot identifies the order (0, 1, or 2 respectively). (3) Half-life method: measure $t_1$/2 at different [A]_0. Constant $t_1$/2 = first order. $t_1$/2 proportional to [A]_0 = zero order. $t_1$/2 proportional to 1/[A]_0 = second order. General: n = 1 - log$\frac{t_1/2_2/t_1/2_1}{log}$([A]_0_2/[A]_0_1). (4) Differential method (log-log plot): plot log(rate) vs log[A]. Slope = order m. JEE preference: initial rates method is most commonly tested as a tabular data problem. Integrated rate law problems typically give two data points and ask for k. Key check: verify units of k match the determined order.