Why is the probability of reaction with molecularity higher than three very rare ?

Reaction : $KCl{O_3} + 6FeS{O_4} + 3{H_2}S{O_4} \to $ $KCl + 3F{e_2}{\left( {S{O_4}} \right)_3} + 3{H_2}O$

Which is True $(T)$ and False $(F) $ in the following sentence ?

The reaction is complex.

The rate of the reaction $CC{l_3}CHO + NO \to CHC{l_3} + NO + CO$ is given by Rate $ = K\,[CC{l_3}CHO]\,[NO]$. If concentration is expressed in moles/litre, the units of K are

Write unit of rate constant of following reaction :

$1.$ $\frac {5}{2}$ order

$2.$  $n$ order

The experimental data for decomposition of $N _{2} O _{5}$

$\left[2 N _{2} O _{5} \rightarrow 4 NO _{2}+ O _{2}\right]$

in gas phase at $318 \,K$ are given below:

$(i)$ Plot $\left[ N _{2} O _{5}\right]$ against $t$

$(ii)$ Find the half-life period for the reaction.

$(iii)$ Draw a graph between $\log \left[ N _{2} O _{5}\right]$ and $t$

$(iv)$ What is the rate law $?$

$(v)$ Calculate the rate constant.

$(vi)$ Calculate the half-life period from $k$ and compare it with $(ii)$.

${A_2} + {B_2} \to 2AB;R.O.R = k{[{A_2}]^a}{[{B_2}]^b}$

Order of reaction with respect to $A_2$ and $B_2$ are respectively