How is the movement of particles in diffusion determined?

Diffusion is driven by the concentration gradient and kinetic energy of the particles/molecules that move in random motion and collide with one another. Diffusion is the movement of particles/molecules from an area of high concentration to an area of low concentration. Diffusion process continues until the particles/molecules are evenly distributed in the whole available space.

answer is a

explanation:

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .