2 A 12.34 mL solution with an unknown salt concentration when weighed had a mass of 10.25 g. When the water was evaporated from the solution 4.78 g of NaCl remained. a. Calculate the mass-mass percent NaCl concentration in the solution. b. Calculate the mass-volume percent NaCl concentration in the solution. c. Calculate the molarity of NaCl in the solution. TABLE 5.7 Common Concentration Units and Their Definitions Concentration Unit (Symbol) Definition Mass/mass percent Mass of solute (g) × 100 (m/m%) Mass of solution (g) Mass/volume percent Mass of solute (g) X 100 (m/v %) Volume of solution (mL) Molarity (M) Moles of solute (mol) X 100 Liters of solution (L)