Answer:
J= -K×∆p/∆x × A = Cm²/s.atm × atm.cm²/cm = cm³/s
Explanation:
On the basis of the above considerations, Fick’s First Law may be formulated as:
J = -∆(dc/dx)
In words: The diffusive flux is
proportional to the
existing concentration
gradient.
The negative sign in this relationship indicates that particle flow occurs in a “down”
gradient direction.
J (moles/cm²s)
= - D (dc/dx)
Thus: D = cm2/s
We can now set up the diffusion equation:
J = -K(dp/dx)
Jdx =KdP
( operates with pressures instead
of concentrations)
We may now formally separate the variables and integrate:
Jdx = –KdP
We can forego the integration since (dP/dx) = (∆P/dx) and we may immediately write:
J= -K×∆p/∆x ×A = Cm³/s
