For an elementary reaction,which of the following is correct?

Determine the order of reaction on the basis of following data for the reaction $A + B \to C$.

Exp.	$[A]$	$[B]$	Rate of reaction $(mol \ L^{-1} \ s^{-1})$
$1$	$0.1$	$0.1$	$2 \times 10^{-3}$
$2$	$0.4$	$0.1$	$0.8 \times 10^{-2}$
$3$	$0.1$	$0.2$	$1.6 \times 10^{-2}$

(in $.5$)

For the reaction,$PCl_5 \longrightarrow PCl_3 + Cl_2$,the rate and rate constant are $1.02 \times 10^{-4} \ mol \ L^{-1} \ s^{-1}$ and $3.4 \times 10^{-5} \ s^{-1}$ respectively at a given instant. The molar concentration of $PCl_5$ at that instant is

Assertion: The order of a reaction can have a fractional value.
Reason: The order of a reaction cannot be determined from the balanced chemical equation of a reaction.

The rate constant of esterification is given by $k = k^{\prime} [H_2O]$. If the rate constant $k = 2.0 \times 10^{-3} \ min^{-1}$,calculate $k^{\prime}$. (Assume $[H_2O] = 55.5 \ mol \ L^{-1}$)

For $n$th order of reaction,half-life period is directly proportional to