Determine the masses of potassium nitrate and water required to prepare 400 g

Determine the masses of potassium nitrate and water required to prepare 400 g of a solution with a mass fraction of potassium nitrate 0.05.

The mass of the solution is 400 grams;

To find the mass of salt, it is necessary to multiply its mass fraction by the mass of the solution.

m salt = 400 x 0.05 = 20 grams;

To find the mass of water, subtract the mass of salt from the mass of the solution:

m of water = 400 – 20 = 380 grams;

The density of water is 1 gram / cm3. To prepare this solution, you need to measure out 380 milliliters of water.

Check: 380 + 20 = 400;