Is the diffusion of solvent particles across a semipermeable membrane.

a.) density
b.) solvation
c.) molarity
d.) osmosis

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 .