Question

A saturated solution of NaCl (dissolved in water) has a concentration of 4.01 M at a given temperature. The solution has a volume of 1 L (1000 mL). If the water were to evaporate until the volume of the solution is 500 mL (and then stirred), what would the concentration of the new solution be?

Answer 1

4.01M = 4.01 mols/L soln.
If half of the water is evaporated you now have the same number of mols in 0.5L so 4.01mol/0.5L =?M