Fluxo de massa Flashcards
NERST- PLANK LAW
electrodiffusion
Ions can move due to a potential difference. This will increase the flick’s law (that describes concentration gradient diffusion of particles from highest concentration to lowest concentration) by adding also the electrochemical diffusion of charged particles.
The Nerst-Plank law will describe these two processes
FICK’S LAW
Fick’s first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration (across a concentrate gradient).
Fd= Kd (Ca-Cb)
Fd: The intensity of the diffusion flux measures the amount of substance that will flow through a unit area during a unit time interval.
Ca-Cb: concentration difference from the b side to the a side
Kd: diffusion coefficient from the solute
graph: the flow of solute from the point of higher concentration to the point of lower concentration starts high and with time goes down until it reaches equilibrium and reaches a constrained flow between the two points. Also the concentration tends to reaches equilibrium
Fick’s second law predicts how diffusion causes the concentration to change with respect to time.
It adds the area to the formula
DIFFUSION
Movement of particles from the region containing the highest concentration of solute to the lowest concentration.
Diffusion speed depends of the temperature, particle size and concentration gradient (chemical gradient)
Talk about MASS FLOW
Consists in the movement of particles by their hydraulic pressure difference
The flow moves from the region of highest pressure to the smaller pressure.
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