# To 200 grams of the solution was added 100 grams of water. The mass fraction of the substance is 0.3.

To 200 grams of the solution was added 100 grams of water. The mass fraction of the substance is 0.3. Calculate the mass fraction of the dissolved substance in the resulting solution.

Given:
ω1 = 0.3
m p-pa1 = 200 g
m (H2O) = 100 g

Find:
ω2 -?

Solution:
1) find the mass of dry matter:
m in-va = ω1 * m p-pa1 = 0.3 * 200 = 60 g

2) find the mass of the resulting solution:
m p-pa2 = m p-pa1 + m (H2O) = 200 + 100 = 300 g

3) find the mass fraction in the resulting solution:
ω2 = m in-va / m p-pa2 = 60/300 = 0.2

Answer: the mass fraction of the solute in the resulting solution is 0.2.

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