Answer:
she should add solute to the solvent
Explanation:
Given data :
Mass of the sodium chloride, = 20.0 g
Concentration of the solution = 10 g/L
Volume of 20.0 g of sodium chloride = 7.50 mL
Now, from the concentration, we can conclude that for 10 g of sodium chloride volume of the solution is 1 L
thus, for 20 g of sodium chloride volume of the solution is 2 L or 2000 mL
also,
Volume of solution = Volume of solute(sodium chloride) + volume of solvent (water)
thus,
2000 mL = 7.5 mL + volume of solvent (water)
or
volume of water = (2000 - 7.5) mL
or
volume of water = 1992.5 mL
or
volume of water = 199.25 L ≈ 199 L