From a solution of a mass of 500 grams with a mass fraction of salt of 10% by evaporation, 300 grams

From a solution of a mass of 500 grams with a mass fraction of salt of 10% by evaporation, 300 grams of water was removed. Determine the mass fraction of salt in the resulting solution.

The mass of the solution is 0.5 kilograms.

Let’s find the mass of the substance contained in the solution.

To do this, we multiply its mass fraction by the weight of the solution in grams.

m salt = 500 x 0.1 = 50 grams;

To find the mass of water, it is necessary to subtract the mass of the solute from the mass of the solution:

m water = m solution – m salt = 500 – 50 = 450 grams;

Check: 50 + 450 = 500;

300 grams of water was evaporated from the initial solution.

Its mass will decrease and will amount to 500 – 300 = 200 grams.

We find the mass fraction of salt in the new solution by dividing the weight of the salt by the new mass of the solution.

With salt 2 = 50/200 = 0.25 = 25%;