For a first-order reaction involving gaseous reactants and gaseous products,what will be the unit of its rate constant?

When the value of rate constant $(k)$ is $2.0 \text{ min}^{-1}$, then what will be the half-life of the reaction $(t_{1/2})$ in seconds?

$A$ first order reaction is found to have a rate constant,$k = 5.5 \times 10^{-14} \ s^{-1}$. The half life of reaction is . . . . . . .

The time of completion of $90\%$ of a first order reaction is approximately

$A$ first order reaction has a rate constant $0.00813 \ min^{-1}$. How long will it take for $60 \%$ completion (in $min$)?

Initial concentration of reactant in a first order reaction is $0.08 \text{ mol dm}^{-3}$. What concentration would remain after $40 \text{ minutes}$? (Given $\frac{[A]_0}{[A]_t} = 5.00$)