5 ml of water was evaporated from 230 g of 10% potassium chloride solution.

5 ml of water was evaporated from 230 g of 10% potassium chloride solution. What is the mass fraction of salt in the solution?

Given:
m1 solution (KCl) = 230 g
ω1 (KCl) = 10%
V (H2O) = 5 ml

To find:
ω2 (KCl) -?

Decision:
1) m (KCl) = ω1 * m1 solution / 100% = 10% * 230/100% = 23 g;
2) m (H2O) = ρ * V = 1 * 5 = 5 g;
3) m2 solution (KCl) = m1 solution (KCl) – m (H2O) = 230 – 5 = 225 g;
4) ω2 (KCl) = m * 100% / m2 solution = 23 * 100% / 225 = 10.2%.

Answer: The mass fraction of KCl is 10.2%.