To 300 g of a solution, the mass fraction of the substance in which is 10%, 200 g of water was added

To 300 g of a solution, the mass fraction of the substance in which is 10%, 200 g of water was added. Calculate the mass fraction of the solute in the resulting solution.

Given:
m1 solution (in-va) = 300 g
ω1 (in-va) = 10%
m (H2O) = 200 g

To find:
ω2 (in-va) -?

1) Calculate the mass of the substance in the original solution:
m1 (in-va) = ω1 * m1 solution / 100% = 10% * 300/100% = 30 g;
2) Determine the mass of the substance in the final solution:
m2 (in-va) = m1 (in-va) = 30 g;
3) Calculate the mass of the final solution:
m2 solution (in-va) = m1 solution (in-va) + m (H2O) = 300 + 200 = 500 g;
4) Calculate the mass fraction of the substance in the final solution:
ω2 (in-va) = m2 * 100% / m2 solution = 30 * 100% / 500 = 6%.

Answer: The mass fraction of the substance is 6%.