For the reaction, $2 \mathrm{SO}_2+\mathrm{O}_2 \rightleftharpoons 2 \mathrm{SO}_3$, the rate of disappearance of $\mathrm{O}_2$ is $2 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$. The rate of appearance of $\mathrm{SO}_3$ is

The temperature coefficient of a reaction is 2. When the temperature is increased from $30^{\circ} \mathrm{C}$ to $90^{\circ} \mathrm{C}$, the rate of saction is increased by

The value of rate constant of a pseudo first order reaction