Calculate the mass of alkali and water required to prepare 300 grams of a 15% solution.

The solution consists of two components. Dissolved substance and solvent.

The weight of the solution is 300 grams.

Let’s calculate the weight of the salt.

To do this, we multiply the weight of the solution by the mass fraction of vitriol.

M substance = 300 x 0.15 = 45 grams;

We calculate the weight of the solvent in a similar way.

M solvent = 300 x 0.85 = 255 grams;

Check: M vitriol + M solvent = M solution = 45 + 255 = 300 grams;