Which of the following is a unimolecular reaction?

The reaction $2N_2O_5 \rightleftharpoons 4NO_2 + O_2$ follows first order kinetics. Hence,the molecularity of the reaction is

The rate constant for a reaction is $10.8 \times 10^{-5} \ mol \ L^{-1} \ s^{-1}$. The order of the reaction is .......

The reaction $2A + B_{2} \rightarrow 2AB$ is an elementary reaction. For a certain quantity of reactants,if the volume of the reaction vessel is reduced by a factor of $3,$ the rate of the reaction increases by a factor of $.....$. (Round off to the Nearest Integer).

Which of the following options correctly represents the relationship between $t_{7/8}$ and $t_{1/2}$ where $t_{7/8}$ represents the time required for the concentration to become $1/8$ of the original for a reaction of order $n$?

For the reaction $2A + 2B \rightarrow 2C + D$,the rate law is expressed as $\text{rate} = k[A]^2[B]$. Calculate the rate constant if the rate of reaction is $0.24 \ mol \ dm^{-3} \ s^{-1}$ where $[A] = 0.5 \ M$ and $[B] = 0.2 \ M$.