Suppose that one wishes to use reverse osmosis to reduce the salt content of brackish water containing 0.22 M total salt concentration to a value of 0.01 M, thus render- ing it usable for human consumption. What is the mini- mum pressure that needs to be applied in the permeators (Figure 18.20) to achieve this goal, assuming that the oper- ation occurs at 298 K? (Hint: Refer to Section 13.5.)