Chemical Kinetics Set-8

Q1. A first-order reaction has a rate constant $k=0.01\ \mathrm{s^{-1}}$. The time required for the concentration to fall to $20\%$ of its initial value is

Q2. For the reaction $\mathrm{A}+\mathrm{B}\rightarrow \text{products}$ the initial rate data at a fixed temperature are:
Experiment I: $[A]_0=0.10\ \mathrm{M},\ [B]_0=0.10\ \mathrm{M},\ \text{rate}=1.0\times10^{-4}\ \mathrm{M\,s^{-1}}$
Experiment II: $[A]_0=0.20\ \mathrm{M},\ [B]_0=0.10\ \mathrm{M},\ \text{rate}=4.0\times10^{-4}\ \mathrm{M\,s^{-1}}$
Experiment III: $[A]_0=0.10\ \mathrm{M},\ [B]_0=0.20\ \mathrm{M},\ \text{rate}=2.0\times10^{-4}\ \mathrm{M\,s^{-1}}$
Which expression represents the rate law and what is the value of the rate constant $k$ (with units)?

Q3. For a reaction obeying $r=k[A]^n$, experimental observation shows that when $[A]$ is increased by a factor of $4$, the initial rate increases by a factor of $8$. The order $n$ with respect to $A$ is

Q4. Consider consecutive first-order reactions $\mathrm{A}\xrightarrow{k_1}\mathrm{B}\xrightarrow{k_2}\mathrm{C}$ with $k_1=1.0\ \mathrm{s^{-1}}$, $k_2=3.0\ \mathrm{s^{-1}}$ and initial $[A]_0=1.0\ \mathrm{M}$. At what time $t$ does $[\mathrm{B}]$ attain its maximum value?