1. Convert Units:

* Target Solution: 525 mL of 5.00 mM SrCl2 needs to be converted to liters (L) and moles per liter (M):

* 525 mL = 0.525 L

* 5.00 mM = 0.00500 M

2. Calculate Moles of SrCl2 in Target Solution:

* Use the formula: moles = molarity × volume

* moles of SrCl2 = 0.00500 M × 0.525 L = 0.002625 moles

3. Calculate Volume of Stock Solution:

* Use the formula: volume = moles / molarity

* volume of 2.40 M SrCl2 = 0.002625 moles / 2.40 M = 0.001094 L

4. Convert to Milliliters:

* 0.001094 L = 1.094 mL

Answer: You need 1.094 mL of 2.40 M SrCl2 to prepare 525 mL of 5.00 mM SrCl2.