For a first order reaction,the initial concentration of a reactant is $0.05 \ M$. After $45 \ minutes$,it is decreased by $0.015 \ M$. Calculate the half-life period $(t_{1/2})$ (in $min$)?

For a first order reaction,show that the time required for $99 \%$ completion is twice the time required for the completion of $90 \%$ of the reaction.

$A$ first order reaction has a rate constant of $1.5 \times 10^{-3} \ s^{-1}$. How long will $5.0 \ g$ of this reactant take to reduce to $3.0 \ g$?

For the first-order gaseous reaction $A_{(g)} \to 2B_{(g)} + C_{(g)}$,the expression for the rate constant $K$ in terms of initial pressure $P_0$ and total pressure $P_t$ at time $t$ is:

For a first order reaction $(A) \rightarrow$ products,the concentration of $A$ changes from $0.1 \ M$ to $0.025 \ M$ in $40 \ min$.
The rate of reaction when the concentration of $A$ is $0.01 \ M$ is ............$ \times 10^{-4} \ M/min$.

Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of $3.33 \ h$ at $25^{\circ} C$. After $9 \ h$,the fraction of sucrose remaining is $f$. The value of $\log _{10} (\frac{1}{f})$ is ..... $\times 10^{-2}$. (Rounded off to the nearest integer) [Assume : $\ln 10 = 2.303, \ln 2 = 0.693$ ]