NCAE Chemistry: Sodium chloride is dissolved in water as given in the choices. Which solution is the
      most concentrated?
            a. 20 g salt dissolved in 25 ml of H2O         c. 6 g salt dissolved in 5 g of H2O
            b. 15 g salt dissolved in 18 ml of H2O         d. 10 g of salt dissolved in 20 g of H2O