If NaCl has a solubility of 36.0 g in 100 g of H2O at 20 °C, how many moles of water are needed to prepare a saturated solution containing 0.263 mol of NaCl at 20 °C?

Answer 1

A solubility of 36.0 g NaCl/100 g H2O is 36.0/58.44 = 0.616 mol NaCl.
100 g H2O is 100/18 = about 5.55 mols H2O so the solubility in terms of mols/mols is 0.616 mols NaCl/5.55 mols H2O.

5.55 mols H2O x (0.263/0.616) = ? mols H2O to prepare a saturated solution.