Which of the following determines the rate of a multistep reaction?

At $345 \ K$,the half-life for the decomposition of a sample of a gaseous compound initially at $55.5 \ kPa$ was $340 \ s$. When the pressure was $27.8 \ kPa$,the half-life was found to be $170 \ s$. The order of the reaction is $......$ [integer answer]

Write the unit of the rate constant for the following reactions:
$1.$ $\frac{1}{2}$ order
$2.$ $\frac{3}{2}$ order

The decomposition of ozone in the upper atmosphere is catalyzed by nitric oxide. The mechanism of the reaction is as follows:
$2NO \rightleftharpoons N_2O + [O]$
$O_3 + [O] \to 2O_2$ (slow)
Determine the order of the reaction.

From the rate expression for the following reaction,determine its order of reaction and the dimensions of the rate constant: $(iv) \ C_{2}H_{5}Cl_{(g)} \rightarrow C_{2}H_{4(g)} + HCl_{(g)} \quad \text{Rate} = k[C_{2}H_{5}Cl]$

Identify the order of reaction for which the unit of the rate constant is $\text{mol dm}^{-3} \text{s}^{-1}$.