The concentration of the reactant in the first-order is reduced to $\frac{1}{{\mathrm{e}}^2}$ of the initial concentration after

(Natural life $=\frac{1}{ \mathrm{K}}$)

The following data are for the decomposition of ammonium nitrite in aqueous solution,

The order of reaction is:

In a hypothetical reaction, $\mathrm{A}\left(\mathrm{aq}\right)\rightleftharpoons 2\mathrm{B}\left(\mathrm{aq}\right)+\mathrm{C}\left(\mathrm{aq}\right)$ (first-order decomposition), $\text{'}\mathrm{A}\text{'}$ is optically active (dextro-rotatory) while $\text{'}\mathrm{B}\text{'}$ and $\text{'}\mathrm{C}\text{'}$ are optically inactive, but $\text{'}\mathrm{B}\text{'}$ takes part in a titration reaction (fast reaction) with ${\mathrm{H}}_2{\mathrm{O}}_2$. Hence, the progress of the reaction can be monitored by measuring the rotation of plane polarised light or by measuring volume of ${\mathrm{H}}_2{\mathrm{O}}_2$ consumed in titration.

In an experiment, the optical rotation was found to be $\mathrm{\theta }=40° \mathrm{at} \mathrm{t}=20 \min \mathrm{and} \mathrm{\theta }=10° \mathrm{at} \mathrm{t}=50 \min$ from start of the reaction. If the progress had been monitored by titration method, volume of ${\mathrm{H}}_2{\mathrm{O}}_2$ consumed at $\mathrm{t}=15 \min$ (from start) is $40 \mathrm{mL}$, then volume of ${\mathrm{H}}_2{\mathrm{O}}_2$ consumed at $\mathrm{t}=60 \min$ will be

For the following parallel chain reaction, the overall half-life of $\mathrm{A}$ is $12$ hours if the rate of formation of $\mathrm{C}$ is $60\%$ of the rate of decomposition of $\mathrm{A}$, then what will be the half-life of $\mathrm{A}$ while it is converting into $\mathrm{B}$?

The Arrhenius relationship of two different reactions is shown below. Which reaction is faster of a lower temperature and which is more sensitive to changes of temperature?

The potential energy diagram for the reaction $\mathrm{R}⟶\mathrm{P}$ is given below: $\mathrm{\Delta H}°$ of the reaction corresponds to the energy