Question

An apparatus has been created to measure the diffusion coefficient of carbon through iron. It is composed of a chamber filled with a carbon rich gas. A 0.5 m long iron pipe passes through the chamber. A gas with very little carbon flows through the pipe and a detector on the exit of the pipe counts the total amount of carbon atoms flowing out of the pipe with time, giving J = 0.032 mol/day. The outer and inner diameter of the pipe are 4.2 cm and 3.4 cm, respectively. The carbon in the iron has a molar fraction of 0.01 on the outer surface of the tube and a molar fraction of 0.009 on the inner surface. The iron has a density of 7.874 g/cm3 and you will need to look up the atomic weight.

a. From this experiment, what is the interdiffusion coefficient of carbon through iron?

b. If the interdiffusion coefficient for carbon through iron can be calculated using D₀=1.1x10^-6 m²/s and Q = 87400 J/mol, what is the temperature in the apparatus?

Answer 1