Casey is completing an experiment that requires a 300 ml solution with a 20% concentration of potassium chloride (kcl). but casey's lab only stores potassium chloride at concentrations of 10% and 50%. how much 10% kcl solution will casey have to mix with 50% kcl solution to make 300 ml of 20% kcl solution? a. 30 ml b. 75 ml c. 225 ml d. 300 ml