For feeding cabbage, a solution with a mass fraction of potassium chloride of 0.04 is used.

For feeding cabbage, a solution with a mass fraction of potassium chloride of 0.04 is used. How to prepare 120 g of such a solution?

The weight of the existing solution is 120 grams;

To find the weight of the salt, it is necessary to multiply its mass fraction by the weight of the solution.

m salt = 120 x 0.04 = 4.8 grams;

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

m water = m solution – m salt = 120 – 4.8 = 115.2 grams;

Check: 120 + 4.8 = 120;

The sum of the found weights of salt and water gives the initial weight of the solution.