A first order reaction is half-completed in $45$ minutes. How long does it need for $99.9\%$ of the reaction to be completed?

A substance $\text{'}\mathrm{A}\text{'}$ decomposes by a first order reaction starting initially with $\left[\mathrm{A}\right]=2.00 \mathrm{M}$ and after $200 \min , \left[\mathrm{A}\right]$ becomes $0.15 \mathrm{M}$. For this reaction, ${\mathrm{t}}_{1/2}$ is

The plot of $\ln$(concentration) of the reactant vs time, for a reaction is a straight line with a negative slope. The reaction follows a

The temperature dependence of rate constant $\left(\mathrm{k}\right)$ of a chemical reaction is written in terms of the Arrhenius equation, $\mathrm{k}={\mathrm{Ae}}^{-{\mathrm{E}}_{\mathrm{a}}/\mathrm{RT}}$. The activation energy $\left({\mathrm{E}}_{\mathrm{a}}\right)$ of the reaction can be calculated by plotting

The reaction $\mathrm{A}\to \mathrm{B}$ follows the first-order kinetics. The time taken for $0.8$ mole of $\mathrm{A}$ to produce $0.6$ mole of $\mathrm{B}$ is $1$ hour. What is the time taken for the conversion of $0.9$ mole of $\mathrm{A}$ to produce $0.675$ mole of $\mathrm{B}?$

For a first-order reaction $\mathrm{A}⟶\mathrm{B}$, the reaction rate at reactant concentration of $0.01 \mathrm{mol} {\mathrm{L}}^{-1}$ is found to be $2.0\times {10}^{-5} \mathrm{mol} {\mathrm{L}}^{-1}{\mathrm{s}}^{-1}.$ The half life period of the reaction is

The rate constant of a reaction at temperature $200 \mathrm{K}$ is $10$ times less than the rate constant at $400 \mathrm{K}.$ What is the activation energy of the reaction?

The time taken for $90\%$ of a first order reaction to complete is approximately: