Assume that a portable reverse-osmosis apparatus operates on seawater, whose concentrations of constituent ions are listed in Table 18.5, and that the desalinated water output has an effective molarity of about 0.02 M. What minimum pressure must be applied by hand pumping at 297 K to cause reverse osmosis to occur?
In Table 18.5

Ionic Constituent Salinity Concentration (M) 0.55 0.47 0.028 0.054 0.010 0.010 2.3 10-3 8.3 X 104 4.3 x 104 9.1 10 7.0 x 105 19.35 Chloride, Cl. Sodium, Na Sulfate, SO4 Magnesium, Mg* Calcium, Ca2+ Potassium, K Carbon dioxide Bromide, Br Boric acid, H3BO3 Strontium, Sr2+ Fluoride, F 10.76 2.71 1.29 0.412 0.40 0.106 0.067 0.027 0.0079 0.0013