Question

Casey is completing an experiment that requires 300 mL of potassium chloride (KCl) at a concentration of 0.2 M. But Casey's lab only stores potassium chloride at concentrations of 0.1 M and 0.5 M. How much 0.1 M KCl will Casey have to mix with 0.5 M KCl to make 300 mL of 0.2 M KCl?
A.
30 mL
B.
75 mL
C.
225 mL
D.
300 mL