Answer:
225 mL of water must be added.
Step-by-step explanation:
First we calculate how many HCl moles are there in 516 mL of a 0.191 M solution:
- 516 mL * 0.191 M = 98.556 mmol HCl
Now we use that number of moles (that remain constant during the dilution process) to calculate the final volume of the 0.133 M solution:
- 98.556 mmol / 0.133 M = 741 mL
We can calculate the volume of water required from the volume difference: