BASIC PRINCIPLES
Review
For the reaction NO + NO3 → 2NO2 , the rate of reaction can be expressed as
r = - d[NO]/dt = - d[NO3]/dt = + ½ d[NO2]/dt
Order of Reaction
Returning to the simple reaction, A →B, defining the rate of the reaction doesn't tell the whole story. The order of the reaction must also be known. For the given example the order, n, can be determined such that:
Rate a [A]n
For the general case, aA + bB → Product(s), the rate of the reaction is:
Rate a [A]α[B]βwhere the overall order of the reaction is (α + β), the order with respect to (wrt) A is α and the order wrt B is β.
Review Question
For the experimentally determined rate of reaction, r a [NO]2[O2], it can be stated that
Overall Order = 1, Order wrt NO = 2, Order wrt O2 = 1Overall Order = 2, Order wrt NO = 1, Order wrt O2 = 1