To 300 g of a solution with a mass fraction of a solute equal to 0.4, 100 g of water was added. The mass fraction

To 300 g of a solution with a mass fraction of a solute equal to 0.4, 100 g of water was added. The mass fraction of the dissolved substance in the resulting solution is equal to.

Given:
m1 (solution) = 300g
W1 (in-va) = 0.4
mAdd (H2O) = 100g
To find:
W2 (in-va) -?
Decision:
m (in-va) = W1 (in-va) * m1 (solution) = 0.4 * 300 = 120g
m2 (solution) = m1 (solution) + maddition (H2O) = 300 + 100 = 400g
W2 (in-islands) = (100 * m (in-islands)) / m2 (solution) = (100 * 120) / 400 = 30%
Answer: W2 (in-va) = 30%