Which of the following is a unimolecular reaction?

The unit of the rate constant for a second-order reaction is ....

The order of a reaction can have:

The decomposition of dimethyl ether leads to the formation of $CH_4$,$H_2$ and $CO$ and the reaction rate is given by
Rate $= k [CH_3OCH_3]^{3/2}$
The rate of reaction is followed by increase in pressure in a closed vessel,so the rate can also be expressed in terms of the partial pressure of dimethyl ether,i.e.
Rate $= k (p_{CH_3OCH_3})^{3/2}$
If the pressure is measured in $bar$ and time in $minutes$,then what are the units of rate and rate constants?

$A$ complex reaction takes place in $2$ steps:
$(I)$ $NO_{2(g)} + F_{2(g)} \rightarrow NO_2F_{(g)} + F_{(g)}$ (slow)
$(II)$ $F_{(g)} + NO_{2(g)} \rightarrow NO_2F_{(g)}$ (fast)
Identify the reaction intermediate.

Write the differential rate expression for the following reaction and determine its order of reaction:
$5 Br^{-} + BrO_3^{-} + 6 H^{+} \rightarrow 3 Br_2 + 3 H_2 O$