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

The reaction $X \rightarrow$ products is a first order reaction. In $40 \ min$,the concentration of $X$ changes from $1.0 \ M$ to $0.25 \ M$. What is the rate of reaction when $[X] = 0.1 \ M$? $(\log 4 = 0.60)$

The half-life period for a first order reaction is $693 \ sec$. The rate constant for this reaction would be: (in $sec^{-1}$)

For a reaction,$r = k[A]$. If $50 \%$ of $A$ is decomposed in $120 \ \text{minutes}$,the time taken for $90 \%$ decomposition of $A$ is $............ \ \text{minutes}$.

In a first-order reaction,the rate constant $k = 70 \, s^{-1}$. How much time is required for the concentration to become $\frac{1}{18}$ of the initial concentration (in $, s$)?

For the first$-order$ reaction,$T_{av}$ (average life),$T_{50}$ and $T_{75}$ in the increasing order are: