Linearity of a Rxn

[705984992]

Why do some reactions show non-linear dependence on the reaction concentration? Why is the graph for a zeroth order linear but for a first or second order, it's not linear. What makes it not linear?

[mehaksk]

Reactions show non-linear dependence on reactant concentration when their rates are proportional to the concentration (first-order) or its square (second-order) because the rate changes as the reactants are consumed. Zeroth-order reactions are linear since the rate is constant regardless of concentration. Non-linearity in first and second-order reactions arises because the probability of reactant collisions affecting the rate differs as the concentration changes: exponentially for first-order and with the square for second-order.

[Charlotte Norris 2K]

the reaction rate of zero order reactions is not dependent on concentration, and first and second order reactions are affected differently by concentration changes, thus the graphs of each type of reaction differ depending on how you are graphing k versus concentration