Answer:
Volume of the concentrated solution, which is needed is 103.30 mL
Explanation:
Let's apply the formula for dilutions to solve the problem
Conc. Molarity . Conc. volume = Dil. Molarity . Dil volume
12.1 M . Conc. volume = 2.5 M . 500 mL
Conc. volume = (2.5 M . 500 mL) / 12.1M
Conc. volume = 103.30 mL
