19.1-2. Equimolar Counterdiffusion of NH, and N2 at Steady State. Ammonia gas (4) and nitrogen gas (B) are diffusing in counterdiffusion through a straight glass tube 2.0 ft (0.610 m) long with an inside diameter of 0.080 ft (24.4 mm) at 298 K and 101.32 kPa. Both ends of the tube are connected to large mixed chambers at 101.32 kPa. The partial pressure of NH3 is constant at 20.0 kPa in one chamber and at 6.666 kPa in the other. The diffusivity at 298 K and 101.32 kPa is 2.30 x 10m/s (a) Calculate the diffusion of NH3 in lb mol/h and kg mol/s. (b) Calculate the diffusion of N2. (c) Calculate the partial pressures at a point 1.0 ft (0.305 m) in the tube and plot PA.PB, and P versus distance z. Ans. (a) Diffusion of NH3 = 7.52 x 107 lb mol A/h, 9.48 x 10-11 kg mol A/s; (c) PA = 1.333 x 10' Pa