A gas phase elementary reaction A 2B takes place in a 10L PFR, which is followed in series by a CSTR. Pure A is fed to the PFR at 1 mol/sec. The reaction reaches 60% conversion in the PFR, which is then fed to the CSTR. What volume CSTR is needed to raise the conversion to 90%? Please consider the expansion factor since it is a gas phase reaction. Do not copy existing solutions on the internet