A 15% solution of Hcl with a mass of 200 was added 500 g of a 100% solution of the same acid.

A 15% solution of Hcl with a mass of 200 was added 500 g of a 100% solution of the same acid. Determine the mass fraction of acid in the resulting solution.

1) Find m (HCl stuff) in solution.

m (HCl) = 0.15 * 200 g = 30 g

2) Since the acid concentration in the second solution is 100%, then m (HCl) = 500 g

3) Find the masses of the whole substance and the entire solution:

m (things HCl) = 30 g + 500 g = 530 g

m (pa-pa) = 200 g + 500 g = 700 g

4) We make the proportion:

700 g – 100%

530 g – x

x = 530 g * 100: 700 g = 75.7%

Answer: the concentration of HCl in the resulting solution is 75.7%.