What volume of 0.50 M CaCl2 solution is needed to prepare 250 mL of solution that has a chloride concentration of 0.100 M?
25.0 mL
2 moles of Cl− are created when every mole of CaCl2 is dissolved.
Total moles of chloride ion required: 250×0.1=25mmol
V× 0.5× 2 = 25 m mol
V = 25 ml