Estimation of effective diffusivity in a porous solid.Estimate the diffusivity of N2 in H2 in the pores of a catalyst at 300oC and 20 atm if the porosity is 0.45 and the tortuosity is 2.5.Assume ordinary molecular diffusion in the pores.

Show a clear step solution to a), b) and c)

The three lines below represent grain boundary, surface and self -diffusion in an unspecified metal. Match each line with the type of diffusion. This can be done by comparing the activation energy. Activation energy for surface diffusion is expected to have the lowest activation energy whereas volume diffusion the greatest.

Determine the binary diffusion coefficient of H2 in air a.) at 400 K and 0.8 atm in m2/s.b.) at 600 K and 3 atm in m2/s. c.) at 200 K and 1 atm in m2/s.

What is the difference between slurry adsorption (contact filtration) and fixed-bed adsorption (percolation)? When should each be considered and not considered?

Which of the following statements relating to the sintering of ceramics are false? 1. The driving force for sintering is the reduction of internal interface energy. 2. The source of mass transport at coarsening stage is mainly surface. 3. Sintering involves heating the ceramic to above its melting point. 4. The larger the particle size, the higher the sintering rate would be. 5. Lower temperatures promote diffusion of atoms and mass transport. 2, 4 and 5 1, 2 and 3 O O 1, 3 and 4 1, 2 and 5 3, 4 and 5

In this type of Fickian diffusion, the diffusing species is moving through a "stagnant" bed of another species in solution.   -Unsteady-state Diffusion -None of the choices -Unimolecular Diffusion -Knudsen Diffusion -Equimolar Counter Diffusion

Find the percent ionization of a 0.250 M HC2H3O2 solution at 25 °C.

2. Explain why a solid solution consisting of 2 metals is stronger than either of the pure constituent metals.

Material Science please help