Question

A patient is to prepare one liter of a 1:5000 potassium permanganate (KMnO4) solution as a foot soak. You have a stock solution of KMnO4,5%. How many milliliters of the stock solution must be used to prepare one liter of the foot soak?

Answer 1

1:5000 means 1 kg of KMnO4 in 5000 L of the solution.

So in 5000 L of solution, amount of KMnO4= 1 kg

In 1 L of solution, KMnO4= 1/5000= 2 * 10^-4 L = 0.2 gram

5% stock solution means 5 gram of KMnO4 in 100 ml of solution.

0.2 gram = 20 *0.2 = 4 ml of solution .