The mass of NaCl present in a 1 molar solution of NaCl in water depends on the volume of the solution. For example, 1 liter of solution contains 58.44 grams NaCl. The mass of the solute is directly proportional to the volume of solution.
The molar concentration or molarity of a solution indicates the number of moles of a compound present in 1 liter of solution. The mass of 1 mole of a compound is simply the sum of the atomic masses of each atom present.
NaCl contains one sodium atom (22.99 grams) and one chlorine atom (35.45 grams), resulting in a molar mass of 58.44 grams. To maintain the concentration, 2 liters of solution must contain 2 moles of solute. Therefore, 2 liters of 1 molar solution of NaCl contains 116.88 grams NaCl.