What is the volume of this solution?

Question

The molarity of a sodium hydroxide solution is 0.2 M. The molar mass of NaOH is 40 g/mol.

If 20 g of sodium hydroxide (NaOH) is dissolved in water in this solution, what is the volume of the solution? 

Answer 1

20 g NaOH x 1 mol/40 g = 0.5 moles NaOH

To make a 0.2 M solution with 0.5 moles, what must the final volume be?

0.5 moles / x L = 0.2 moles/ 1 L

x = 2.5 L = volume of the solution