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2.10 Ammonia is being cracked on a solid catalyst according to the reaction 2NH, N2 + 3H2 At one place in the apparatus, where the pressure is 1 std atm abs and the temperature 200C, the analysis of the bulk gas is 33.33% NH, (A), 16.67% N2 (B), and 50.00% H2 (C) by volume. The circumstances are such that NH, diffuses from the bulk-gas stream to the catalyst surface, and the products of the reaction diffuse back, as if by molecular diffusion through a gas film in laminar flow 1 mm thick. Estimate the local rate of cracking, kg NHZ/(m2 catalyst surface) . s, which might be considered to occur if the reaction is diffusion-controlled (chemical reaction rate very rapid) with the concentration of NH, at the catalyst surface equal to zero