The rate constant of a first order reaction is $1.15 \times 10^{-3} \ s^{-1}$. How long will $5 \ g$ of reactant take to reduce to $3 \ g$ (in $s$)?

Which is the correct relation between rate constant and half-life of a first-order reaction?

For the reaction $A_{(g)} \rightarrow B_{(g)} + C_{(g)}$,the rate law is $R = k[A]$. At the start $(t = 0)$,the total pressure is $100 \ mm$ and after $t = 10 \ min$,the total pressure is $120 \ mm$. The rate constant $(min^{-1})$ is:

$PCl_{5(g)} \rightarrow PCl_{3(g)} + Cl_{2(g)}$
In the above first order reaction,the concentration of $PCl_{5}$ reduces from an initial concentration of $50 \ mol \ L^{-1}$ to $10 \ mol \ L^{-1}$ in $120 \ minutes$ at $300 \ K$. The rate constant for the reaction at $300 \ K$ is $X \times 10^{-2} \ min^{-1}$. The value of $X$ is $......$
$[$ Given $\log 5 = 0.6989 ]$

Find the rate constant of a first-order reaction in $sec^{-1}$ having a half-life of $2.5 \ hours$.

The half-life period of a first-order reaction is $1386 \text{ s}$. The rate constant of the reaction is: