How much salt and water is needed to prepare a 300g 15% solution?

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

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

Find the weight of the dissolved salt.

M salt = 300 x 0.15 = 45 grams;

Similarly, we find the weight of the solvent (water).

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

M water = 300 x 0.85 = 255 grams = 255 ml;

Let’s check. To do this, we sum up the masses of the components of the solution and obtain the mass of the solution in question.

255 + 45 = 300;