A zero-order gas phase reaction $A \rightarrow B$ with rate $\left(-r_{A}\right)=k=100 \mathrm{~mol} /(\mathrm{L \: min )}$ is carried out in a mixed flow reactor of volume $1 \: L$ . Pure $A$ is fed to the reactor at a rate of $1 \mathrm{~mol} / \mathrm{min}$. At time $t=0$, the outlet flow is stopped while the inlet flow rate and reactor temperature remain unchanged. Assume that the reactor was operating under steady state before the flow was stopped $(t<0)$. The rate of consumption of $A,-d C_{A} / d t$, in $\mathrm{mol} /(\mathrm{L \: min})$, at $t=1 \mathrm{~min}$ is
- $63.2$
- $36.8$
- $90.6$
- $99.0$
