The osmotic pressure, , of sea water is given approximately by the expression = RTc/M, where c

The osmotic pressure, π, of sea water is given approximately by the expression π = RTc/M, where c is the concentration of the dissolved salts (solutes) in g/cm3 and M is the average molecular weight of the solutes as ions. If pure water is to be recovered from sea water at 298 K and containing 0.035 g of salts/cm3 of sea water and M = 31.5, what is the minimum required pressure difference across the membrane in kPa?