Answer :
Answer:
[tex]X_B = 1.8 \times 10^{-3} m = 1.8 mm[/tex]
Explanation:
Given data:
Diffusion constant for nitrogen is [tex]= 1.85\times 10^{-10} m^2/s[/tex]
Diffusion flux [tex]= 1.0\times 10^{-7} kg/m^2-s[/tex]
concentration of nitrogen at high presuure = 2 kg/m^3
location on which nitrogen concentration is 0.5 kg/m^3 ......?
from fick's first law
[tex]J = D \frac{C_A C_B}{X_A X_B}[/tex]
Take C_A as point on which nitrogen concentration is 2 kg/m^3
[tex]x_B = X_A + D\frac{C_A -C_B}{J}[/tex]
Assume X_A is zero at the surface
[tex]X_B = 0 + ( 12\times 10^{-11} ) \frac{2-0.5}{1\times 10^{-7}}[/tex]
[tex]X_B = 1.8 \times 10^{-3} m = 1.8 mm[/tex]