Higher order $(> 3)$ reactions are rare due to:

........ of a reaction cannot be determined experimentally.

For a reaction $A \to B$,the rate of reaction quadrupled when the concentration of $A$ is doubled. The rate expression of the reaction is $r = K[A]^n$. The value of $n$ is

Reaction: $KClO_3 + 6FeSO_4 + 3H_2SO_4 \to KCl + 3Fe_2(SO_4)_3 + 3H_2O$
Which is True $(T)$ and False $(F)$ in the following statement?
The order of this reaction is $10$.

For a certain chemical reaction $X \rightarrow Y$,the rate of formation of the product is plotted against time as shown in the figure. The number of correct statement$(s)$ from the following is $.......$.
$A$. Overall order of this reaction is one
$B$. Order of this reaction cannot be determined
$C$. In region-$I$ and $III$,the reaction is of first and zero order respectively
$D$. In region-$II$,the reaction is of first order
$E$. In region-$II$,the order of reaction is in the range of $0.1$ to $0.9$.

Which of the following statements is $NOT$ true about the rate constant $k$?