Question

The molarity of a solution prepared by dissolving 15.0 grams of NaCl in 100 mL water is 0.15 M.
True or False

Answer 1

Probably you want moles NaCl = grams/molar mass, then
M = mols/L soln. Technically, however, you can't solve this problem without knowing the density BECAUSE adding 15.0 g NaCl to 100 mL water is not the same as adding 15.0 g NaCl to enough water to make 100 mL of SOLUTION. If I were answering the question I would answer false and argue with the prof if s/he counted it wrong but for the reason I just cited and not the fact that 15.0 g/100 mL SOLN is 2.56M soln.

Answer 2

True