Which law states that the amount of a substance crossing a given area is directly proportional to the area available for diffusion, concentration gradient and diffusion coefficient?
Fick Law of Diffusion:
Diffusion is well described by Fick law of diffusion. According to this law, amount of a substance crossing a given area is directly proportional to the area available for diffusion, concentration gradient and a constant known as diffusion coefficient.
Thus, 
Amount diffused = Area x Concentration gradient x Diffusion coefficient
Formula of Fick law:
Universal gas law
Dalton's law
Fick's law
All of the above