To 340 g of a solution with a mass fraction of salt of 20% poured 160 g of water.

To 340 g of a solution with a mass fraction of salt of 20% poured 160 g of water. Calculate the mass fraction of salt in the resulting solution.

Given:
m1 solution (salt) = 340 g
ω1 (salt) = 20%
m (water) = 160 g

Find:
ω2 (salt) -?

Solution:
1) m1 (salts) = ω1 (salts) * m1 solution (salts) / 100% = 20% * 340/100% = 68 g;
2) m2 (salt) = m1 (salt) = 68 g;
2) m2 solution (salt) = m1 solution (salt) + m (water) = 340 + 160 = 500 g;
3) ω2 (salt) = m2 (salt) * 100% / m2 solution (salt) = 68 * 100% / 500 = 13.6%.

Answer: The mass fraction of salt is 13.6%.