What volume of 1.30 M SrCl2 is needed to prepare 525 mL of 5.00 mM SrCl2?

Answer 1

Sometimes mM can be confusing and one can avoid the confusion by converting to M.
5.00 mM = 0.005 M
M = moles/L
You know M and you know L, solve for moles = M x L = 0.005 x 0.525 = ??
Then moles = grams/molar mass
You know moles and molar mass, solve for grams.