What is the half-life of a first-order reaction if the time required to decrease the concentration of the reactant from $0.8 \text{ M}$ to $0.2 \text{ M}$ is $12 \text{ hours}$ (in $\text{ hours}$)?

For a homogeneous gaseous reaction $A_{(g)} \to 3B_{(g)}$,if the pressure after time $t$ is $P_t$ and after completion of the reaction the pressure is $P_\infty$,select the correct relation for the rate constant $K$.

In a first order reaction $A \to B,$ if $k$ is the rate constant and the initial concentration of the reactant $A$ is $0.5 \ M,$ then the half-life is:

For a first-order reaction $SO_2Cl_2 \to SO_2 + Cl_2$ at $320\, ^\circ C$,the rate constant is $2.2 \times 10^{-5}\, s^{-1}$. What percentage $(\%)$ of $SO_2Cl_2$ will decompose upon heating for $90\, min$?

At $300 \ K$,a gaseous reaction $A(g) \longrightarrow B(g) + C(g)$ follows first-order kinetics. Starting with pure $A$,the total pressure at the end of $20 \ min$ is $100 \ mm \ of \ Hg$. The total pressure after the completion of the reaction is $180 \ mm \ of \ Hg$. The partial pressure of $A$ at $20 \ min$ (in $mm \ of \ Hg$) is:

The rate constant of the decomposition of hydrogen peroxide is $0.0204 \text{ min}^{-1}$. Calculate the half-life of the reaction. (in $\text{ min}$)