How many grams of potassium nitrite KNO3 will be required to prepare a solution

How many grams of potassium nitrite KNO3 will be required to prepare a solution weighing 50 g with a mass fraction of potassium nitrate 25%?

Let us find the masses of the constituent components of the solution.

This requires multiplying their mass fraction by the weight of the solution.

Determine the weight of the dissolved salt.

M salt = 50 x 0.25 = 12.5 grams;

In the same way, we find the weight of the solvent (water).

(In the calculations, we take the density of water equal to 1 gram / cm3).

M water = 50 x 0.75 = 37.5 grams = 37.5 ml;

Let’s check. To do this, add the masses of the components of the solution and get the mass of the required solution.

37.5 + 12.5 = 50;