A liquid containing a solvent, flows down a vertical plane. The free surface of the liquid...

 

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A liquid containing a solvent, flows down a vertical plane. The free surface of the liquid is in contact with a gas, and the solvent diffuses out of the liquid into the gas. The initial concentration of the solvent is Co = 0.1M. At the liquid/gas interface the film velocity is 12 cm/s (i.e. Vmax.) The diffusion coefficient is D = 8 10-m/s. At the top of the film no solvent has diffused into the gas, and C = Co. At the gas/liquid interface (liquid side) the concentration is C = 0.0 mol/m because the solvent is infinitely diluted. Let z be the vertical axis, with z = 0 at the top, and x is the horizontal axis, with its origin at the liquid/gas interface and positive towards the wall. The total length is z = L =160 cm, the width W = 100 cm. The governing equation for the solvent diffusion in the liquid is 2 x 1. Use the similarity transformation ac Vmax = z DA X n = 2 DAZ/Vmax to write the problem in terms of n, then solve for the concentration C in terms of n. 2. What is the flux at the liquid/gas interface in terms of z and x? How does the flux change with z? 3. Find the total molar flow of solvent at x = 0 (the gas/liquid interface). A liquid containing a solvent, flows down a vertical plane. The free surface of the liquid is in contact with a gas, and the solvent diffuses out of the liquid into the gas. The initial concentration of the solvent is Co = 0.1M. At the liquid/gas interface the film velocity is 12 cm/s (i.e. Vmax.) The diffusion coefficient is D = 8 10-m/s. At the top of the film no solvent has diffused into the gas, and C = Co. At the gas/liquid interface (liquid side) the concentration is C = 0.0 mol/m because the solvent is infinitely diluted. Let z be the vertical axis, with z = 0 at the top, and x is the horizontal axis, with its origin at the liquid/gas interface and positive towards the wall. The total length is z = L =160 cm, the width W = 100 cm. The governing equation for the solvent diffusion in the liquid is 2 x 1. Use the similarity transformation ac Vmax = z DA X n = 2 DAZ/Vmax to write the problem in terms of n, then solve for the concentration C in terms of n. 2. What is the flux at the liquid/gas interface in terms of z and x? How does the flux change with z? 3. Find the total molar flow of solvent at x = 0 (the gas/liquid interface).