The rate constant of a first order reaction is $1.15 \times 10^{-3} \ s^{-1}$. How long will $5 \ g$ of reactant take to reduce to $3 \ g$ (in $s$)?

If the half-life period of a first order reaction is $138.6 \ minutes$,then the value of the decay constant for the reaction will be:

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 a first order reaction,the intercept of the graph between $\log \left(\frac{[A]_0}{[A]_t}\right)$ ($Y$-axis) and time ($X$-axis) is equal to

For a first order reaction,the half-life period is independent of

For the first order reaction with rate constant $k$,which expression gives the half-life period? (Initial concentration $= a$)