The half life for the decomposition of gaseous compound $A$ is $240\,s$ when the gaseous pressure was $500\,Torr$ initially. When the pressure was $250\,Torr$, the half life was found to be $4.0\,min$. The order of the reaction is....... (Nearest integer)

Reaction : $2Br^{-} + H_2O_2 + 2H^{+} \to  Br_2 + 2H_2O$

take place in two steps :

$(a)$ $Br^{-} + H^{+} + H_2O_2 \xrightarrow{{slow}} HOBr + H_2O$

$(b)$ $HOBr + Br^{-} + H^{+} \xrightarrow{{fast}} H_2O + Br_2$

The order of the reaction is 

For which order reaction a straight line is obtained along with $x\,-$ axis by plotting a graph between half life $({t_{1/2}})$ and initial concentration $ 'a'$

Calculate the order of the reaction in $A$ and $B$

The unit of rate constant for a zero order reaction is

The half-life of $2 $ sample are $0.1 $ and $ 0.4 $ seconds. Their respective concentration are $200 $ and  $ 50 $ respectively. What is the order of the reaction