Consider the elementary, gas-phase reaction: AB. Industry standards for product B require a purity of at least 92%. To obtain this product, pure A is fed into a single PFR, but the resulting purity of B is only 85%. To solve this problem, you propose to add a CSTR with the same volume (i.e., equal size as the PFR) in series before the PFR, using the same initial feed (pure A, at the same conditions). (a) Would the resulting final product now meet the industrial standard? (b) What is the final purity of B, with the CSTR added to the PFR? Hint: Note that because both the PFR and CSTR are run at the same temperature, are at steady-state, and have the same volume, the value of " (or, Da number) is the same in both reactors. Assume all processes are run under isothermal and isobaric conditions, and are at steadystate. Assume also that there are no side reactions, so A converts only to B (and nothing else). State all other assumptions, and show all your work