What is the unit of the rate constant for a first-order reaction?

The half-life for the first-order reaction $N_2O_5 \to 2NO_2 + \frac{1}{2} O_2$ is $2.4 \text{ hours}$. Starting with $10.8 \text{ g}$ of $N_2O_5$ at $STP$,how many liters of oxygen will be obtained after a period of $9.6 \text{ hours}$? (Given: $10^{0.2} = 1.584$)

The first order decomposition of $H_2O_2$ in an appropriate medium is characterised by a rate constant of $0.2303 \ min^{-1}$. What is the time (in $min$) required to complete $9/10$ fraction of the reaction?

For a first-order reaction,the half-life period is $6 \ min$. Find the rate constant of the reaction. (in $min^{-1}$)

For two first-order reactions:
$A \rightarrow \text{Products}$
$B \rightarrow \text{Products}$
If at the same time,$50\% \, B$ has reacted and $94\% \, A$ has reacted,calculate the ratio $K_1/K_2$.

The following results were obtained during kinetic studies of the reaction $2A + B \to$ products:

Experiment	$[A]$ $(mol \ L^{-1})$	$[B]$ $(mol \ L^{-1})$	Initial rate $(mol \ L^{-1} \ min^{-1})$
$I$	$0.10$	$0.20$	$6.93 \times 10^{-3}$
$II$	$0.10$	$0.25$	$6.93 \times 10^{-3}$
$III$	$0.20$	$0.30$	$1.386 \times 10^{-2}$

The time (in minutes) required to consume half of $A$ is: