Answer
To obtain a 0.750 M $CaCl_2$ solution, we should dilute that initial solution to 667 mL.
Work Step by Step
1. Find the necessary volume:
$C_1 * V_1 = C_2 * V_2$
$ 5.00 M * 100 mL= 0.75 M * V_2$
$ 500 M*mL = 0.75 M * V_2$
$V_2 = \frac{500 M*mL}{0.75 M}$
$V_2 = 667 mL$
