measuring. Diluting 4.5 liters of 8.0 Molar glycerol with an equal portion of water would make 9 liters of 4.0 Molar glycerol solution, but it would not be an isotonic solution. The 9 liters would only contain 40.95 grams (9.1 X 4.5) of NaCl. Another 40.95 grams of NaCl is added by adding about 200 mL of the concentrated NaCl solution.