Calculate a sample for the preparation of 200 g of 0.9% NaCl solution.

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

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

Let’s calculate the weight of the dissolved salt.

M salt = 200 x 0.009 = 1.8 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 = 200 x (1 – 0.009) = 198.2 grams;

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

198.2 + 1.8 = 200;