The rate constant of a first order reaction was doubled when the temperature was increased from 300 to 310 K . What is its approximate activation energy (in $\mathrm{kJ} \mathrm{mol}^{-1}$ )? ( $R=8.3 \mathrm{Jmol}^{-1} \mathrm{~K}^{-1}: \log 2=0.3$ )

$A \rightarrow P$ is a zero order reaction. At 298 K the rate constant of the reaction is $1 \times 10^{-3} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$. Initial concentration of ' $A$ ' is $0.1 \mathrm{~mol} \mathrm{~L}^{-1}$. What is the concentration of ' $A$ after 10 sec ?

The rate constant of a first order reaction is $3.46 \times 10^{-2} \mathrm{~s}^{-1}$ at 298 K . What is the rate constant of the reaction at 350 K if its activation energy is $50.1 \mathrm{~kJ} \mathrm{~mol}^{-1}$, $\left(R=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\right)(\log 2=0.3010)$