Final answer:
The reaction order is determined by the exponents in the rate law equation, representing the dependency of the reaction rate on reactant concentrations. The overall reaction order is the sum of these exponents. Experimental data regarding concentration and rate changes are used to determine these orders, employing differential or integrated rate laws.
Step-by-step explanation:
Understanding Rate Laws and Reaction Order
When classifying the rate law of a reaction, one must consider the mathematical dependency of the reaction rate on the concentrations of its reactants. This dependency is expressed through the order of the reaction with respect to each reactant, often represented as exponents in the rate law equation. The overall reaction order is the sum of these individual orders.
For instance, if a reaction's rate law is given by the expression rate = k[A]m[B]n, and we are told that m=1 and n=2, then the reaction would be first order with respect to A, second order with respect to B, and third order overall. The rate constant, k, can also be determined by substituting known concentrations and reaction rates into the rate law equation. Patterns in the initial concentrations' changes and the corresponding changes in initial reaction rates help to deduce whether a reaction is zeroth-, first-, or second-order.
To derive the specific order for a given reaction, experimental data are essential. These data can be manipulated using either differential rate laws or integrated rate laws, which are interconnected mathematical forms that describe how concentration changes affect the reaction rate over time. The exponents within the rate law determine the power dependence of the rate on reactant concentrations, thus indicating the order of the reaction.