Why can we not determine the order of a reaction by taking into consideration the balanced chemical equation?

(N/A) The balanced chemical equation represents the overall stoichiometry of a reaction but does not necessarily reflect the mechanism or the rate-determining step.
$1.$ The order of a reaction is an experimental quantity,whereas the stoichiometry is derived from the balanced equation.
$2.$ Many reactions are complex and occur in multiple steps. The rate of the overall reaction is determined by the slowest step in the mechanism.
$3.$ For example,consider the reaction: $CHCl_3 + Cl_2 \rightarrow CCl_4 + HCl$. Based on the stoichiometry,one might incorrectly predict a second-order reaction,but the experimental rate law is $Rate = k[CHCl_3][Cl_2]^{1/2}$,which is of order $1.5$.
$4.$ Thus,the order of a reaction cannot be determined simply by looking at the balanced chemical equation.