The thermal decomposition of a molecule follows a first-order reaction. The molecule decomposes $50\%$ in $120 \text{ minutes}$. How many minutes will it take for $90\%$ decomposition?

For the first-order reaction $N_2O_5 \to 2NO_2 + \frac{1}{2}O_2$,the half-life at $30 \ ^\circ C$ is $24 \ \text{hours}$. Starting with $10 \ g$ of $N_2O_5$,how many grams of $N_2O_5$ will remain after $96 \ \text{hours}$ (in $g$)?

Calculate the time required for a reactant to decrease in concentration from $100 \%$ to $20 \%$,if the rate constant of the first-order reaction is $0.02303 \ hour^{-1}$. (in $hour$)

If the rate constant of a reaction is $x \, sec^{-1}$,by what factor does the rate increase if the initial concentration of $A$ is tripled?

For the first order reaction $A \to \text{Product}$ $(t_{1/2} = 10 \ \text{min})$,the fraction of reactant degraded after an hour from the reaction has started is

If the concentration is expressed in $mol \ L^{-1}$,the unit of the rate constant for a first-order reaction is........