Chemistry
posted by Hannah .
What is the osmotic pressure formed by dissolving 50.8 mg of aspirin (C9H8O4) in 0.200 L of water at 18°C?

mols = grams/molar mass.Solve for mols.
M = mols/L. Solve for M.
pi = MRT. Solve for pi = osmotic pressure. 
I did that. doesnt it have to be liters of the total solution? so how do we factor in the asprin into the liters?

I beg to differ but you did not do that. If you had you would have the answer now.
mols = 50.8E3g/180.2 = about 0.0003 but you need to do it more accurately.
Then 0.0003 mols/0.200L = about 0.0014
Then pi = MRT