The time of half change of a first order reaction is ....... initial concentration.

In a first-order reaction,the concentration of the reactant decreases from $1.0 \, M$ to $0.25 \, M$ in $20 \, \text{minutes}$. What will be the rate constant of the reaction?

The reaction $2A \rightarrow \text{Product}$ follows first-order kinetics. If the initial concentration $[A]_0 = 0.2 \ mol \ L^{-1}$ and the half-life period $t_{1/2} = 20 \ min$,calculate the rate constant $k$.

The half-life period of a reaction is $1386 \ s$. What is the value of the specific rate constant for the reaction?

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

Half-life of a first order reaction is $20 \ s$ and initial concentration of reactant is $0.2 \ M$. The concentration of reactant left after $80 \ s$ is (in $M$)