Question

Directions: Additional information to complete these problems can be found in your Examination Booklet. Write all Engineering Notation to the tenth place only.

--Given Values--
Temperature 1 in Celsius = 803
Thickness of Palladium Sheet in mm = 2.4
Area of Palladium sheet (m²) = 0.33
Thickness of Sheet of Steel (mm) = 4.69
Diffusion Flux (kg/(m²-s)) = 6.26E-07
Temperature 2 in Celsius = 1049

Problem 1:

Calculate the value of the diffusion coefficient D (in m²/s) at Temperature 1 shown above,for the diffusion of some species in a metal; assume that the values of Do and Qd are 5.6x10^-5 m²/s and 177 kJ/mol, respectively. (Answer in Engineering Notation)

        Your Answer =

Problem 2:

The purification of hydrogen gas is possible by diffusion through a thin palladium sheet. Calculate the number of kilograms of hydrogen that pass per hour through a thick sheet of palladium having an area and thickness listed above at 500C. Assume a diffusion coefficient of 8.9x10^-8 m²/s, that the concentrations at the high- and low-pressure sides of the plates are 3.3 and 0.64 kg/m³ of hydrogen per cubic meter of palladium, and that steady-state conditions have been attained.(Answer in Engineering Notation)

        Your Answer =

Problem 3:

A sheet of steel has a thickness listed above, it also has nitrogen atmospheres on both sides at 1200C and is permitted to achieve a steady-state diffusion condition. The diffusion coefficient for nitrogen in steel at this temperature is 6.6X10^-11 m²/s, and the diffusion flux is listed above. Also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 5.9 kg/m³. How far into the sheet from this high-pressure side will the concentration be 2.5 kg/m³? Assume a linear concentration profile. (Answer in 0.00 mm)

        Your Answer =

Problem 4:

Compute the diffusion coefficient (diffusivity) for the interstitial diffusion of carbon in alpha-iron (BCC) at Temperature 2 shown above. (Answer in Engineering Notation)

        Your Answer =

Problem 5:

Compute the diffusion coefficients (diffusivity) for the interstitial diffusion of carbon in gamma-iron (FCC) at Temperature 2 shown above. (Answer in Engineering Notation)

        Your Answer =

Answer 1