A membrane has pure water on one side of it, and a protein solution on the other side. The membrane has pores equivalent in size to a spherical molecule with a molecular weight (Mm) of 120,000 daltons. The protein solution consists of albumin (40 g/L at Mm = 69,000 daltons), globulins (70 g/L at MW = 150,000 daltons), and fibrinogen (60 g/L at Mm = 340,000 daltons). Assume that T=25 C and the proteins form an ideal solution.
a. What is the osmotic pressure of this protein solution?
b. What would be the osmotic pressure of the protein solution if the membrane was completely impermeable to all the proteins?