Determine the amount of water needed to add to 20.3 mL of a 2.78 M iron (III) chloride, FeCl₃, stock solution to make a 2.50 M solution.

• A. 0.29 mL
• B. 22 mL
• C. 0.28 mL
• D. 2.3 mL

Answer: (D)