2. A heat exchanger made of a sheet of FCC iron (thickness = 1 mm) is used to store the nitrogen gas at 1200 °C. The concentration of N at one surface is 0.04 at% and the concentration at the opposite surface is 0.005 at%. Evaluate the flux of nitrogen through the foil in N atoms/(m².s). Given that the gas constant, R = 8.314 Jmol ¹K-1 and use the diffusion data in the Table 1 for your calculation. Diffusion Couple Q (kJ/mol) Do (m²/s) ×10-4 Interstitial diffusion: C in FCC iron 137.7 C in BCC iron 87.5 N in FCC iron 144.7 N in BCC iron 76.6 0.23 0.011 0.0034 0.0047 Table 1: Diffusion data for selected materials