1, (25 pts) Pure gas A is contained in a large container as shown in the figure
The pressure in the container is 1 atm. The temperature is 25 °C. The container is
connected to catalyst by a conduit, and an instantaneous reaction on the catalyst
surface goes as A $\rightarrow$ 3B. The conduit is 10 m in length. The cross section of the
conduit is a square, the length of each side of the square being 0.1 m at the left end
and tapering uniformly to 0.3 m at the right end. The volume of the conduit is very
small compared to the containers and therefore can be neglected. Assume that it is
at steady state. The diffusivity $D_{AB}$ is 1 × 10$^{-5}$ m²/s.
Gas Law Constant R = 82.057 × 10$^{-3}$ m³ \cdot atm/kg mol \cdot K
(a), calculate the molar flux $\bar{N}_A$ for in kg mol/s (12 pts).
(b), calculate the flux $N_A$ and $N_B$ at a point in the conduit 2 m to the left end (5 pts).
(c), what is the total pressure at the point 2 m to the left end? Explain (8 pts).
