To 500 g of a 22% solution of the substance, 300 g of a 30% solution of this substance was added.

To 500 g of a 22% solution of the substance, 300 g of a 30% solution of this substance was added. What is the concentration of the resulting mixture?

1. Let’s find the mass of the substance in the first solution.

500 g – 100%,

x g – 22%,

x = (500 g x 22%): 100% = 110 g.

2. Find the mass of the substance in the second solution.

300 g – 100%,

x g – 30%.

x = (300 g x 30%): 100% = 90 g.

3. Find the mass of the resulting solution.

300 g + 500 g = 800 g.

4. Find the mass of the substance in the resulting solution.

90 g + 110 g = 200 g.

5. Find the mass fraction of the substance in the resulting solution.

(m (substance): m (solution) x 100%.

(200g: 800g) x 100% = 25%.

Answer: 25%.