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?
We have to mix 10% KCl solution with 50% KCl solution to get 20% concentration. We have x mL of 10% solution and y mL of 50% solution. 20% - 10% = 10% and 50% - 20% = 30% x : y = 30 : 10 x : y = 3 : 1 x = 3 y x + y = 300 3 y + y = 300 4 y = 300 y = 300 : 4 y = 75 x = 300 - 75 = 225Answer: Casey will have to mix 225 mL 10% KCl solution with 75 mL 50% solution.
