A 0.2M solution of ethanol undergoes reverse osmosis in a module which is operated at a trans-membrane pressure of 55 bar. Concentration polarisation is negligible under the conditions employed. The water permeability of the membrane is 7.0l/m2h/ bar and the manufacturer quotes an intrinsic rejection coefficient of 0.6, obtained at 15 bar with a 0.1M solution under conditions of negligible concentration polarisation. The osmotic pressure (in Pa) of the solution at the temperature employed can be calculated from the equation =kosmc, where the concentration, c, is expressed as a molarity (mol /I) and kosm=2.5106Pal/mol. Calculate the solute permeability and, assuming it is constant, calculate the rejection coefficient at 55 bar