To prepare 400 grams of a 2% salt solution, you need to take a mass of salt?

Let’s calculate the masses of the components of the solution.

To do this, it is necessary to multiply their mass fraction by the weight of the solution.

Let’s calculate the weight of the dissolved salt.

M salt = 400 x 0.02 = 8 grams;

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

(In the calculations, we will make the assumption that the density of water is 1 gram / ml).

M water (solvent) = 400 x 0.98 = 392 grams = 392 ml;

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

392 + 8 = 400;