26.1.2—Rate equations and reaction order

In the initial-rates method, compare experiments where one concentration changes while others stay constant. A factor change in rate reveals the order; concentration–time and rate–concentration graphs provide complementary evidence.

For rate=k[A]^m[B]^n, solve m and n separately, then calculate k with units. A first-order concentration–time curve has a constant half-life.

Doubling [A] leaves rate unchanged → zero order; doubling it doubles rate → first order; quadrupling rate → second order.

Do not infer order from a single experiment or confuse a curved concentration–time plot with a rate–concentration graph.