The rate of a first-order reaction is $0.04 \ mol \ L^{-1} \ s^{-1}$ at $10 \ minutes$ and $0.03 \ mol \ L^{-1} \ s^{-1}$ at $20 \ minutes$ after initiation. The half-life of the reaction is . . . . . . minutes. (Given $\log 2 = 0.3010, \log 3 = 0.4771$)

$A$ flask is filled with equal moles of $A$ and $B$. The half-lives of $A$ and $B$ are $100 \, s$ and $50 \, s$ respectively and are independent of the initial concentration. The time required for the concentration of $A$ to be four times that of $B$ is $.... \, s.$
(Given : $\ln 2 = 0.693$ )

At $T(K)$,if the rate constant of a first order reaction is $4.606 \times 10^{-3} \ s^{-1}$,the time to reduce the initial concentration of the reactant to $1/10$ of its initial value in seconds is:

For a first-order reaction $A \rightarrow \text{Product}$,the rate of reaction is $1 \times 10^{-2} \, \text{mol L}^{-1} \text{min}^{-1}$ when $[A] = 0.2 \, \text{M}$. What is the half-life $(t_{1/2})$ of the reaction?

Consider a general first order reaction $A_{(g)} \rightarrow B_{(g)} + C_{(g)}$. If the initial pressure is $200 \ mm$ and after $20 \ minutes$ it is $250 \ mm$,then the half-life period of the reaction (in minutes) is. $(\log 2 = 0.30, \log 3 = 0.48, \log 4 = 0.60)$

For which of the following reactions is the half-life period independent of the initial concentration of the reactant?