Time required for $99.9 \%$ completion of a first order reaction is . . . . . . . times the time required for completion of $90 \%$ reaction. (nearest integer).

The half-life period of a first-order reaction is $138.6 \ min$. The rate constant of the reaction is: (in $min^{-1}$)

For the reaction $A \to B$,the rate law expression is: $\text{Rate} = k[A]$. Which of the following statements is incorrect?

Consider the first-order gas-phase decomposition reaction given below:
$A_{(g)} \longrightarrow B_{(g)} + C_{(g)}$
The initial pressure of the system before the decomposition of $A$ was $P_i$. After time $t$,the total pressure of the system increased by $x \ units$ and became $P_t$. The rate constant $k$ for the reaction is given as:

Find the time period of a $1^{st}$ order reaction when the reaction is $\frac{2}{3} ^{rd}$ complete. If the value of the rate constant is $4.3 \times 10^{-4} \, s^{-1}$.

In a $1^{st}$ order reaction,$75\%$ of the reactant is consumed in $1.388 \, h$. Find the rate constant of the reaction.